Form 485BPOS VANGUARD SPECIALIZED

Fund Summary

Investment Objective

The Fund seeks to provide a high level of income and moderate long-term capital appreciation by tracking the performance of a benchmark index that measures the performance of publicly traded equity REITs.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold Investor Shares or Admiral Shares of the Fund.

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Examples

The following examples are intended to help you compare the cost of investing in the Fund’s Investor Shares or Admiral Shares with the cost of investing in other mutual funds. They illustrate the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. These examples assume that the shares provide a return of 5% each year and that total annual fund operating expenses remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense examples, reduce the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 7% of the average value of its portfolio.

Principal Investment Strategies

The Fund employs an indexing investment approach designed to track the performance of the MSCI US REIT Index. The Index is composed of stocks of publicly traded equity real estate investment trusts (known as REITs). The Fund attempts to replicate the Index by investing all, or substantially all, of its assets—either directly or indirectly through a wholly owned subsidiary (the underlying fund), which is itself a registered investment company—in the stocks that make up the Index, holding each stock in approximately the same proportion as its weighting in the Index. The Fund may invest a portion of its assets in the underlying fund.

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Principal Risks

An investment in the Fund could lose money over short or even long periods. You should expect the Fund’s share price and total return to fluctuate within a wide range. The Fund is subject to the following risks, which could affect the Fund’s performance:

• Industry concentration risk, which is the chance that the stocks of REITs will decline because of adverse developments affecting the real estate industry and real property values. Because the Fund concentrates its assets in REIT stocks, industry concentration risk is high.

• Stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund’s target index may, at times, become focused in stocks of a limited number of companies, which could cause the Fund to underperform the overall stock market.

• Interest rate risk, which is the chance that REIT stock prices overall will decline and that the cost of borrowing for REITs will increase because of rising interest rates. Interest rate risk is high for the Fund.

• Investment style risk, which is the chance that the returns from REIT stocks—which typically are small- or mid-capitalization stocks—will trail returns from the overall stock market. Historically, REIT stocks have performed quite differently from the overall market.

• Asset concentration risk, which is the chance that, because the Fund’s target index (and therefore the Fund) tends to be heavily weighted in its ten largest holdings, the Fund’s performance may be hurt disproportionately by the poor performance of relatively few stocks.

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

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Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund‘s Investor Shares has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the share classes presented compare with those of the Fund‘s target index and a comparative index, which have investment characteristics similar to those of the Fund. The REIT Spliced Index reflects performance of the MSCI US REIT Index adjusted to include a 2% cash position (Lipper Money Market Average) through April 30, 2009, and the MSCI US REIT Index thereafter. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard REIT Index Fund Investor Shares¹

1 The year-to-date return as of the most recent calendar quarter, which ended on June 30, 2017, was 2.55%.

During the periods shown in the bar chart, the highest return for a calendar quarter was 34.54% (quarter ended September 30, 2009), and the lowest return for a quarter was –38.16% (quarter ended December 31, 2008).

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Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are shown only for the Investor Shares and may differ for each share class. After-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Investment Advisor

The Vanguard Group, Inc. (Vanguard)

Portfolio Managers

Walter Nejman, Portfolio Manager at Vanguard. He has co-managed the Fund since 2016.

Gerard C. O’Reilly, Principal of Vanguard. He has managed the Fund since its inception in 1996 (co-managed since 2016).

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Purchase and Sale of Fund Shares

You may purchase or redeem shares online through our website (vanguard.com), by mail (The Vanguard Group, P.O. Box 1110, Valley Forge, PA 19482-1110), or by telephone (800-662-2739). The minimum investment amount required to open and maintain a Fund account for Investor Shares or Admiral Shares is $3,000 or $10,000, respectively. The minimum investment amount required to add to an existing Fund account is generally $1. Institutional, financial intermediary, and Vanguard retail managed clients should contact Vanguard for information on special eligibility rules that may apply to them regarding Admiral Shares. If you are investing through an employer-sponsored retirement or savings plan, your plan administrator or your benefits office can provide you with detailed information on how to participate in your plan.

Tax Information

The Fund’s distributions may be taxable as ordinary income or capital gain or may constitute non–taxable return of capital. If you are investing through a tax-advantaged account, such as an IRA or an employer-sponsored retirement or savings plan, special tax rules apply.

Payments to Financial Intermediaries

The Fund and its investment advisor do not pay financial intermediaries for sales of Fund shares.

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Investing in Index Funds

What Is Indexing?

Indexing is an investment strategy for tracking the performance of a specified market benchmark, or “index.” An index is a group of securities whose overall performance is used as a standard to measure the investment performance of a particular market. There are many types of indexes. Some represent entire markets—such as the U.S. stock market or the U.S. bond market. Other indexes cover market segments—such as small-capitalization stocks or short-term bonds. The index sponsor determines the securities to include in the index, the weighting of each security in the index, and the appropriate time to make changes to the composition of the index. One cannot invest directly in an index.

An index fund holds all, or a representative sample, of the securities that make up its target index. Index funds attempt to mirror the performance of the target index, for better or worse. However, an index fund generally does not perform exactly like its target index. For example, index funds have operating expenses and transaction costs. Market indexes do not, and therefore they will usually have a slight performance advantage over funds that track them.

Index funds typically have the following characteristics:

• Variety of investments. Most Vanguard index funds generally invest in the securities of a variety of companies and industries.

• Relative performance consistency. Because they seek to track market benchmarks, index funds usually do not perform dramatically better or worse than their benchmarks.

• Low cost. Index funds are inexpensive to run compared with actively managed funds.

They have low or no research costs and typically keep trading activity—and thus brokerage commissions and other transaction costs—to a minimum compared with actively managed funds.

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More on the Fund

This prospectus describes the principal risks you would face as a Fund shareholder. It is important to keep in mind one of the main axioms of investing: generally, the higher the risk of losing money, the higher the potential reward. The reverse, also, is generally true: the lower the risk, the lower the potential reward. As you consider an investment in any mutual fund, you should take into account your personal tolerance for fluctuations in the securities markets. Look for this symbol throughout the prospectus. It is used to mark detailed information about the more significant risks that you would confront as a Fund shareholder. To highlight terms and concepts important to mutual fund investors, we have provided Plain Talk^® explanations along the way. Reading the prospectus will help you decide whether the Fund is the right investment for you. We suggest that you keep this prospectus for future reference.

Share Class Overview

This prospectus offers the Fund‘s Investor Shares and Admiral Shares. Another prospectus offers the Fund‘s Institutional Shares, which are generally for investors who invest a minimum of $5 million. In addition, the Fund issues ETF Shares (an exchange-traded class of shares), which are also offered through a separate prospectus.

All share classes offered by the Fund have the same investment objective, strategies, and policies. However, different share classes have different expenses; as a result, their investment performances will differ.

A Similar But Different Fund

The Fund offered by this prospectus should not be confused with Vanguard REIT II Index Fund, a separate Vanguard fund that also seeks to track the performance of the MSCI US REIT Index and is anticipated to be the underlying fund. Both funds seek to replicate the stocks that make up the target index. This index replication strategy, combined with differences in the funds’ respective cash flows and expenses, is expected to produce slightly different investment performance by the funds. To obtain a prospectus for Vanguard REIT II Index Fund, institutional investors may call Vanguard’s Institutional Division at 888-809-8102 or may call their relationship managers directly.

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The following sections explain the principal investment strategies and policies that the Fund uses in pursuit of its objective. The Fund‘s board of trustees, which oversees the Fund’s management, may change investment strategies or policies in the interest of shareholders without a shareholder vote, unless those strategies or policies are designated as fundamental. Under normal circumstances, the Fund will invest at least 80% of its assets in the stocks that make up its target index. This policy may be changed only upon 60 days‘ notice to shareholders.

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Market Exposure

The Fund invests in stocks of publicly traded equity real estate investment trusts.

The Fund is subject to investment style risk, which is the chance that returns from REIT stocks—which typically are small- or mid-capitalization stocks—will trail returns from the overall stock market. Historically, REIT stocks have performed quite differently from the overall market.

Stocks of publicly traded companies and funds that invest in stocks are often classified according to market value, or market capitalization. These classifications typically include small-cap, mid-cap, and large-cap. It is important to understand that market capitalization ranges change over time. Also, interpretations of size vary, and there are no “official” definitions of small-, mid-, and large-cap, even among Vanguard fund advisors. REITs in the MSCI US REIT Index tend to be small- and mid-cap stocks. The asset-weighted median market capitalization of the Fund’s stock holdings as of January 31, 2017, was $10 billion.

Small- and mid-cap stocks tend to have greater volatility than large-cap stocks because, among other things, smaller companies often have fewer customers, financial resources, and products than larger firms. Such characteristics can make small and mid-size companies more sensitive to changing economic conditions. REIT stocks tend to have a significant amount of dividend income, which can reduce the impact of this volatility. However, the Fund is subject to additional risk because of the concentration in the real estate sector. This focus on a single sector may result in more risk than that for a more diversified, multisector portfolio.

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The Fund is subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund‘s target index may, at times, become focused in stocks of a limited number of companies, which could cause the Fund to underperform the overall stock market.

To illustrate the volatility of stock prices, the following table shows the best, worst, and average annual total returns for the U.S. stock market over various periods as measured by the S&P 500 Index, a widely used barometer of U.S. stock market activity. Total returns consist of dividend income plus change in market price. Note that the returns shown do not include the costs of buying and selling stocks or other expenses that a real-world investment portfolio would incur.

The table covers all of the rolling 1-, 5-, 10-, and 20-year periods from 1926 through 2016. You can see, for example, that although the average annual return on common stocks for all of the 5-year periods was 10.1%, average annual returns for individual 5-year periods ranged from –12.4% (from 1928 through 1932) to 28.6% (from 1995 through 1999). These average annual returns reflect past performance of common stocks; you should not regard them as an indication of future performance of either the stock market as a whole or the Fund in particular.

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The Fund is subject to interest rate risk, which is the chance that REIT stock prices overall will decline and that the cost of borrowing for REITs will increase because of rising interest rates. Interest rate risk is high for the Fund.

In general, during periods of high interest rates, REITs may lose some of their appeal for investors who may be able to obtain higher yields from other income-producing investments, such as long-term bonds. Higher interest rates also mean that financing for property purchases and improvements is more costly and difficult to obtain.

The Fund is subject to industry concentration risk, which is the chance that the stocks of REITs will decline because of adverse developments affecting the real estate industry and real property values. Because the Fund concentrates its assets in REIT stocks, industry concentration risk is high.

Because of its emphasis on REIT stocks, the Fund’s performance may at times be linked to the ups and downs of the real estate market. In general, real estate values can be affected by a variety of factors, including, but not limited to, supply and demand for properties, the economic health of the nation as well as different regions, and the strength of specific industries that rent properties. Ultimately, an individual REIT’s performance depends on the types and locations of the properties it owns and on how well the REIT manages its properties. For instance, rental income could decline because of extended vacancies, increased competition from nearby properties, tenants’ failure to pay rent, regulatory limitations on rents, fluctuations in rental income, variations in market rental rates, or incompetent management. Property values could decrease because of overbuilding in the area, environmental liabilities, uninsured damages caused by natural disasters, a general decline in the neighborhood, losses because of casualty or condemnation, increases in property taxes, or changes in zoning laws. Loss of IRS status as a qualified REIT may also affect an individual REIT’s performance. In addition, many real estate issuers, including REITs, utilize leverage (and some may be highly leveraged), which increases investment risk and could adversely affect the issuer’s operations and market value in periods of rising interest rates.

Security Selection

The Fund attempts to track the investment performance of a benchmark index that measures the performance of publicly traded equity REITs.

The Fund attempts to hold each stock contained in the MSCI US REIT Index either directly or indirectly through the underlying fund in roughly the same proportion as represented in the Index itself. For example, if 5% of the MSCI US REIT Index were made up of the stock of a specific REIT, the Fund would seek to invest approximately the same percentage of its assets in that stock.

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The MSCI US REIT Index is a free-float adjusted market-cap weighted index. It is made up of the stocks of publicly traded equity REITs that meet certain criteria. For example, to be included initially in the Index, a REIT must meet a minimum market capitalization threshold and have enough shares and trading volume to be considered liquid. In line with the Index, the Fund invests in equity REITs only.

The Fund is subject to asset concentration risk, which is the chance that, because the Fund’s target index (and therefore the Fund) tends to be heavily weighted in its ten largest holdings, the Fund’s performance may be hurt disproportionately by the poor performance of relatively few stocks.

As of January 31, 2017, 155 equity REITs were included in the Index. On a quarterly basis, the Index is rebalanced and its current stocks are tested for continued compliance with the guidelines of the Index. A REIT may be removed from the Index because of a decline in market capitalization, because it becomes illiquid, or because of other changes in its status.

Stocks in the MSCI US REIT Index represent a broadly diversified range of property types. The makeup of the Fund, as of January 31, 2017, was:

Other Investment Policies and Risks

The Fund reserves the right to substitute a different index for the index it currently tracks if the current index is discontinued, if the Fund‘s agreement with the sponsor of its target index is terminated, or for any other reason determined in good faith by the Fund’s board of trustees. In any such instance, the substitute index would represent the same market segment as the current index.

The Fund is subject to REIT ownership limitation risk, which is the chance that the Fund may be unable to purchase (or otherwise obtain economic exposure, including through investing in the underlying fund, to) the desired amounts of certain REITs included in its target index.

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The Fund has significant ownership positions in many REITs included in its target index. For tax and other reasons, a REIT imposes limits on how much of its securities investors may own. If an ownership limit is reached, Vanguard may seek to obtain an ownership waiver from the REIT to exceed the limit. If the Fund is unable to obtain a waiver or an existing waiver is terminated, then the Fund may seek to obtain economic exposure to the REIT through alternative means, such as through a total return swap, which may be more costly than owning REIT shares directly. If the Fund is unable to obtain either an ownership waiver or economic exposure to the REIT through alternative means, the Fund may experience increased tracking error. In addition, to maintain its qualification as a regulated investment company for tax purposes, the Fund may be unable to obtain additional economic exposure to certain REITs, which may increase tracking error. Additional measures could be taken in the future in response to REIT ownership limits, including changing the Fund’s investment strategy, limiting additional purchases into the Fund, or any other appropriate action.

The Fund may invest a portion of its assets in the underlying fund. The underlying fund will also employ an indexing investment approach designed to track the performance of the MSCI US REIT Index. The underlying fund’s investments are subject to the same risks as if they were held directly by the Fund. Because the strategy of the underlying fund will be substantially similar to that of the Fund, the principal risks of the Fund’s investment in the underlying fund will not be materially different from the risks associated with the Fund’s other investments. However, the Fund’s investment in the underlying fund is subject to the ongoing existence of the underlying fund and the underlying fund’s ability to provide economic exposure to REITs included in the Fund’s target index.

If the Fund is unable to invest directly or through the underlying fund or to obtain exposure to REITs through alternative means, then the Fund may be unable to own the desired amount of certain REITs, which may increase tracking error.

The Fund may invest in foreign securities to the extent necessary to carry out its investment strategy of holding all, or substantially all, of the stocks that make up the index it tracks.

In addition to investing in common stocks of REITs, the Fund may make other kinds of investments to achieve its objective.

The Fund may invest in derivatives. In general, investments in derivatives may involve risks different from, and possibly greater than, those of investments directly in the underlying securities or assets.

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Generally speaking, a derivative is a financial contract whose value is based on the value of a financial asset (such as a stock, a bond, or a currency), a physical asset (such as gold, oil, or wheat), a market index (such as the S&P 500 Index), or a reference rate (such as LIBOR). The Fund may invest in derivatives only if the expected risks and rewards of the derivatives are consistent with the investment objective, policies, strategies, and risks of the Fund as disclosed in this prospectus. In particular, derivatives will be used only when they may help the advisor to accomplish one or more of the following:

• Invest in eligible asset classes with greater efficiency and lower cost than is possible through direct investment.

• Obtain economic exposure to a stock, a basket of stocks, or an index when deemed desirable or necessary.

• Add value when these instruments are attractively priced.

The market for many derivatives is, or suddenly can become, illiquid, which may result in significant, rapid, and unpredictable changes in the prices for derivatives. The Fund‘s use of a derivative subjects it to the risk of nonperformance by the counterparty, potentially resulting in delayed or partial payment or even nonpayment of amounts due under the derivative contract. The Fund attempts to mitigate this risk by requiring the posting of collateral by its counterparty.

The Fund‘s derivative investments may include total return swaps or other derivatives.

Cash Management

The Fund‘s daily cash balance may be invested in one or more Vanguard CMT Funds, which are very low-cost money market funds. When investing in a Vanguard CMT Fund, the Fund bears its proportionate share of the expenses of the CMT Fund in which it invests. Vanguard receives no additional revenue from Fund assets invested in a Vanguard CMT Fund.

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Methods Used to Meet Redemption Requests

Under normal circumstances, the Fund typically expects to meet redemptions with other positive cash flows. When this is not an option, the Fund seeks to maintain its risk exposure by selling a cross section of the Fund’s holdings, including by making requests for redemptions from the underlying fund, to meet redemptions, while also factoring in transaction costs. Additionally, the Fund may work with larger clients to implement their redemptions in a manner that is least disruptive to the portfolio; see “Potentially disruptive redemptions.”

Under certain circumstances, including under stressed market conditions, there are additional tools that the Fund may use in order to meet redemptions, including advancing the settlement of market trades with counterparties to match investor redemption payments or delaying settlement of an investor’s transaction to match trade settlement within regulatory requirements. The Fund may also suspend payment of redemption proceeds for up to seven days; see “Emergency circumstances.” Additionally under these unusual circumstances, the Fund may borrow money (subject to certain regulatory conditions and if available under board-approved procedures) through an interfund lending facility or through a bank line-of-credit, including a joint committed credit facility, in order to meet redemption requests.

Temporary Investment Measures

The Fund may temporarily depart from its normal investment policies and strategies when the advisor believes that doing so is in the Fund‘s best interest, so long as the departure is consistent with the Fund‘s investment objective. For instance, the Fund may invest beyond its normal limits in derivatives or exchange-traded funds that are consistent with the Fund‘s objective when those instruments are more favorably priced or provide needed liquidity, as might be the case when the Fund receives large cash flows that it cannot prudently invest immediately.

Frequent Trading or Market-Timing

Background. Some investors try to profit from strategies involving frequent trading of mutual fund shares, such as market-timing. For funds holding foreign securities, investors may try to take advantage of an anticipated difference between the price of the fund’s shares and price movements in overseas markets, a practice also known as time-zone arbitrage. Investors also may try to engage in frequent trading of funds holding investments such as small-cap stocks and high-yield bonds. As money is shifted into and out of a fund by a shareholder engaging in frequent trading, the fund incurs costs for buying and selling securities, resulting in increased brokerage and administrative costs. These costs are borne by all fund shareholders, including the long-term investors who do not generate the costs. In addition, frequent trading may interfere with an advisor’s ability to efficiently manage the fund.

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Policies to address frequent trading. The Vanguard funds (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund) do not knowingly accommodate frequent trading. The board of trustees of each Vanguard fund (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund) has adopted policies and procedures reasonably designed to detect and discourage frequent trading and, in some cases, to compensate the fund for the costs associated with it. These policies and procedures do not apply to Vanguard ETF^® Shares because frequent trading in ETF Shares generally does not disrupt portfolio management or otherwise harm fund shareholders. Although there is no assurance that Vanguard will be able to detect or prevent frequent trading or market-timing in all circumstances, the following policies have been adopted to address these issues:

• Each Vanguard fund reserves the right to reject any purchase request—including exchanges from other Vanguard funds—without notice and regardless of size. For example, a purchase request could be rejected because the investor has a history of frequent trading or if Vanguard determines that such purchase may negatively affect a fund’s operation or performance.

• Each Vanguard fund (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund) generally prohibits, except as otherwise noted in the Investing With Vanguard section, an investor’s purchases or exchanges into a fund account for 30 calendar days after the investor has redeemed or exchanged out of that fund account.

• Certain Vanguard funds charge shareholders purchase and/or redemption fees on transactions.

See the Investing With Vanguard section of this prospectus for further details on Vanguard’s transaction policies.

Each Vanguard fund (other than retail and government money market funds), in determining its net asset value, will use fair-value pricing when appropriate, as described in the Share Price section. Fair-value pricing may reduce or eliminate the profitability of certain frequent-trading strategies.

Do not invest with Vanguard if you are a market-timer.

Turnover Rate

Although the Fund generally seeks to invest for the long term, it may sell securities regardless of how long they have been held. Generally, an index fund sells securities in response to redemption requests from shareholders of conventional (not exchange-traded) shares or to changes in the composition of its target index. The Financial Highlights section of this prospectus shows historical turnover rates for the Fund. A

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turnover rate of 100%, for example, would mean that the Fund had sold and replaced securities valued at 100% of its net assets within a one-year period.

The Fund and Vanguard

The Fund is a member of The Vanguard Group, a family of more than 190 mutual funds holding assets of approximately $3.7 trillion. All of the funds that are members of The Vanguard Group (other than funds of funds) share in the expenses associated with administrative services and business operations, such as personnel, office space, and equipment.

Vanguard Marketing Corporation provides marketing services to the funds. Although shareholders do not pay sales commissions or 12b-1 distribution fees, each fund (other than a fund of funds) or each share class of a fund (in the case of a fund with multiple share classes) pays its allocated share of the Vanguard funds’ marketing costs.

To the extent that the Fund’s assets are invested in another Vanguard fund, including a wholly owned subsidiary, such assets will be excluded when allocating to the Fund its share of the costs of Vanguard’s operations.

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Investment Advisor

The Vanguard Group, Inc. (Vanguard), P.O. Box 2600, Valley Forge, PA 19482, which began operations in 1975, serves as advisor to the Fund through its Equity Index Group. As of January 31, 2017, Vanguard served as advisor for approximately $3.2 trillion in assets. Vanguard provides investment advisory services to the Fund on an at-cost basis, subject to the supervision and oversight of the trustees and officers of the Fund.

For the fiscal year ended January 31, 2017, the advisory expenses represented an effective annual rate of 0.01% of the Fund’s average net assets.

For a discussion of why the board of trustees approved the Fund’s investment advisory arrangement, see the most recent semiannual report to shareholders covering the fiscal period ended July 31.

The managers primarily responsible for the day-to-day management of the Fund are:

Walter Nejman, Portfolio Manager at Vanguard. He has been with Vanguard since 2005, has worked in investment management since 2008, and has co-managed the Fund since 2016. Education: B.A., Arcadia University; M.B.A., Villanova University.

Gerard C. O’Reilly, Principal of Vanguard. He has been with Vanguard since 1992, has managed investment portfolios since 1994, and has managed the Fund since its inception in 1996 (co-managed since 2016). Education: B.S., Villanova University.

The Statement of Additional Information provides information about each portfolio manager’s compensation, other accounts under management, and ownership of shares of the Fund.

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Dividends, Capital Gains, and Taxes

Fund Distributions

Each March, June, September, and December, the Fund pays out to shareholders virtually all of the distributions it receives from its REIT investments, less expenses. Distributions may include income, return of capital, and capital gains. The Fund may also realize capital gains on the sale of its REIT investments. Distributions of these gains, if any, are included in the December distribution. In addition, the Fund may occasionally make a supplemental distribution at some other time during the year.

You can receive distributions of income or capital gains or return of capital in cash, or you can have them automatically reinvested in more shares of the Fund. However, if you are investing through an employer-sponsored retirement or savings plan, your distributions will be automatically reinvested in additional Fund shares.

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Basic Tax Points

Vanguard (or your intermediary) expects to send you a statement each February showing the tax status of all of your distributions. (Other Vanguard funds mail their tax statements in January; the Fund mails its statements later because REITs do not provide information on the taxability of their distributions until after the calendar year-end.) In addition, investors in taxable accounts should be aware of the following basic federal income tax points:

• Distributions (other than any return of capital) are taxable to you whether or not you reinvest these amounts in additional Fund shares.

• Distributions declared in December—if paid to you by the end of January—are taxable as if received in December.

• Any dividend distribution or short-term capital gains distribution that you receive is taxable to you as ordinary income. If you are an individual and meet certain holding-period requirements with respect to your Fund shares, you may be eligible for reduced tax rates on “qualified dividend income,” if any, distributed by the Fund. Dividend distributions attributable to the Fund’s REIT investments are generally not eligible for qualified dividend income treatment.

• Any distribution of net long-term capital gains is taxable to you as long-term capital gains, no matter how long you have owned shares in the Fund.

• Capital gains distributions may vary considerably from year to year as a result of the Fund‘s normal investment activities and cash flows.

• A sale or exchange of Fund shares is a taxable event. This means that you may have a capital gain to report as income, or a capital loss to report as a deduction, when you complete your tax return.

• Dividend distributions attributable to the Fund’s REIT investments are generally not eligible for the corporate dividends-received deduction.

• Your cost basis in the Fund will be decreased by the amount of any return of capital that you receive. This, in turn, will affect the amount of any capital gain or loss that you realize when selling or exchanging your Fund shares.

• Return-of-capital distributions generally are not taxable to you until your cost basis has been reduced to zero. If your cost basis is at zero, return-of-capital distributions will be treated as capital gains.

• Any conversion between classes of shares of the same fund is a nontaxable event. By contrast, an exchange between classes of shares of different funds is a taxable event.

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Individuals, trusts, and estates whose income exceeds certain threshold amounts are subject to a 3.8% Medicare contribution tax on “net investment income.” Net investment income takes into account distributions paid by the Fund and capital gains from any sale or exchange of Fund shares.

Dividend distributions and capital gains distributions that you receive, as well as your gains or losses from any sale or exchange of Fund shares, may be subject to state and local income taxes.

This prospectus provides general tax information only. If you are investing through a tax-advantaged account, such as an IRA or an employer-sponsored retirement or savings plan, special tax rules apply. Please consult your tax advisor for detailed information about any tax consequences for you.

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General Information

Backup withholding. By law, Vanguard must withhold 28% of any taxable distributions or redemptions from your account if you do not:

• Provide your correct taxpayer identification number.

• Certify that the taxpayer identification number is correct.

• Confirm that you are not subject to backup withholding.

Similarly, Vanguard (or your intermediary) must withhold taxes from your account if the IRS instructs us to do so.

Foreign investors. Vanguard funds offered for sale in the United States (Vanguard U.S. funds), including the Fund offered in this prospectus, are not widely available outside the United States. Non-U.S. investors should be aware that U.S. withholding and estate taxes and certain U.S. tax reporting requirements may apply to any investments in Vanguard U.S. funds. Foreign investors should visit the Non-U.S. Investors page on our website at vanguard.com for information on Vanguard’s non-U.S. products.

Invalid addresses. If a distribution check mailed to your address of record is returned as undeliverable, Vanguard will automatically reinvest the distribution and all future distributions until you provide us with a valid mailing address. Reinvestments will receive the net asset value calculated on the date of the reinvestment.

Share Price

Share price, also known as net asset value (NAV), is calculated each business day as of the close of regular trading on the New York Stock Exchange (NYSE), generally 4 p.m., Eastern time. Each share class has its own NAV, which is computed by dividing the total assets, minus liabilities, allocated to the share class by the number of Fund shares outstanding for that class. On U.S. holidays or other days when the NYSE is closed, the NAV is not calculated, and the Fund does not sell or redeem shares. However, on those days the value of the Fund’s assets may be affected to the extent that the Fund holds securities that change in value on those days (such as foreign securities that trade on foreign markets that are open).

Stocks held by a Vanguard fund are valued at their market value when reliable market quotations are readily available from the principal exchange or market on which they are traded. Such securities are generally valued at their official closing price, the last reported sales price, or if there were no sales that day, the mean between the closing bid and asking prices. When a fund determines that market quotations either are not readily available or do not accurately reflect the value of a security, the security is priced at its fair value (the amount that the owner might reasonably expect to receive upon the current sale of the security).

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The values of any foreign securities held by a fund are converted into U.S. dollars using an exchange rate obtained from an independent third party as of the close of regular trading on the NYSE. The values of any mutual fund shares, including institutional money market fund shares, held by a fund are based on the NAVs of the shares. The values of any ETF shares or closed-end fund shares held by a fund are based on the market value of the shares.

A fund also will use fair-value pricing if the value of a security it holds has been materially affected by events occurring before the fund’s pricing time but after the close of the principal exchange or market on which the security is traded. This most commonly occurs with foreign securities, which may trade on foreign exchanges that close many hours before the fund’s pricing time. Intervening events might be company-specific (e.g., earnings report, merger announcement) or country-specific or regional/global (e.g., natural disaster, economic or political news, act of terrorism, interest rate change). Intervening events include price movements in U.S. markets that exceed a specified threshold or that are otherwise deemed to affect the value of foreign securities.

Fair-value pricing may be used for domestic securities—for example, if (1) trading in a security is halted and does not resume before the fund’s pricing time or a security does not trade in the course of a day and (2) the fund holds enough of the security that its price could affect the NAV.

Fair-value prices are determined by Vanguard according to procedures adopted by the board of trustees. When fair-value pricing is employed, the prices of securities used by a fund to calculate the NAV may differ from quoted or published prices for the same securities.

Vanguard fund share prices are published daily on our website at vanguard.com/prices.

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Financial Highlights

The following financial highlights tables are intended to help you understand the Fund’s financial performance for the periods shown, and certain information reflects financial results for a single Fund share. The total returns in each table represent the rate that an investor would have earned or lost each period on an investment in the Fund (assuming reinvestment of all distributions). This information has been obtained from the financial statements audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, whose report—along with the Fund’s financial statements—is included in the Fund‘s most recent annual report to shareholders. You may obtain a free copy of the latest annual or semiannual report by visiting vanguard.com or by contacting Vanguard by telephone or mail.

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1 Total returns do not include transaction or account service fees that may have applied in the periods shown.

2 Excludes the value of portfolio securities received or delivered as a result of in-kind purchases or redemptions of the Fund’s capital shares, including ETF Creation Units.

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1 Total returns do not include transaction or account service fees that may have applied in the periods shown.

2 Excludes the value of portfolio securities received or delivered as a result of in-kind purchases or redemptions of the Fund’s capital shares, including ETF Creation Units.

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Investing With Vanguard

This section of the prospectus explains the basics of doing business with Vanguard. Vanguard fund shares can be held directly with Vanguard or indirectly through an intermediary, such as a bank, a broker, or an investment advisor. If you hold Vanguard fund shares directly with Vanguard, you should carefully read each topic within this section that pertains to your relationship with Vanguard. If you hold Vanguard fund shares indirectly through an intermediary (including shares held through a Vanguard brokerage account), please see Investing With Vanguard Through Other Firms, and also refer to your account agreement with the intermediary for information about transacting in that account. If you hold Vanguard fund shares through an employer-sponsored retirement or savings plan, please see Employer-Sponsored Plans. Vanguard reserves the right to change the following policies without notice. Please call or check online for current information. See Contacting Vanguard.

For Vanguard fund shares held directly with Vanguard, each fund you hold in an account is a separate “fund account.” For example, if you hold three funds in a nonretirement account titled in your own name, two funds in a nonretirement account titled jointly with your spouse, and one fund in an individual retirement account, you have six fund accounts—and this is true even if you hold the same fund in multiple accounts. Note that each reference to “you” in this prospectus applies to any one or more registered account owners or persons authorized to transact on your account.

Purchasing Shares

Vanguard reserves the right, without notice, to increase or decrease the minimum amount required to open, convert shares to, or maintain a fund account or to add to an existing fund account.

Investment minimums may differ for certain categories of investors.

Account Minimums for Investor Shares To open and maintain an account. $3,000.

To add to an existing account. Generally $1.

Account Minimums for Admiral Shares

To open and maintain an account. $10,000. If you request Admiral Shares when you open a new account but the investment amount does not meet the account minimum for Admiral Shares, your investment will be placed in Investor Shares of the Fund. Institutional, financial intermediary, and Vanguard retail managed clients should contact Vanguard for information on special eligibility rules that may apply to them.

To add to an existing account. Generally $1.

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How to Initiate a Purchase Request

Be sure to check Exchanging Shares, Frequent-Trading Limitations, and Other Rules You Should Know before placing your purchase request.

Online. You may open certain types of accounts, request a purchase of shares, and request an exchange through our website or our mobile application if you are registered for online access.

By telephone. You may call Vanguard to begin the account registration process or request that the account-opening forms be sent to you. You may also call Vanguard to request a purchase of shares in your account or to request an exchange. See

Contacting Vanguard.

By mail. You may send Vanguard your account registration form and check to open a new fund account. To add to an existing fund account, you may send your check with an Invest-by-Mail form (from a transaction confirmation or your account statement), with a deposit slip (available online), or with a written request. You may also send a written request to Vanguard to make an exchange. For a list of Vanguard addresses, see Contacting Vanguard.

How to Pay for a Purchase

By electronic bank transfer. You may purchase shares of a Vanguard fund through an electronic transfer of money from a bank account. To establish the electronic bank transfer service on an account, you must designate the bank account online, complete a special form, or fill out the appropriate section of your account registration form. After the service is set up on your account, you can purchase shares by electronic bank transfer on a regular schedule (Automatic Investment Plan) or upon request. Your purchase request can be initiated online (if you are registered for online access), by telephone, or by mail.

By wire. Wiring instructions vary for different types of purchases. Please call Vanguard for instructions and policies on purchasing shares by wire. See Contacting Vanguard.

By check. You may make initial or additional purchases to your fund account by sending a check or by utilizing our mobile application if you are registered for online access. Also see How to Initiate a Purchase Request. Make your check payable to Vanguard and include the appropriate fund number (e.g., Vanguard—xx). For a list of Fund numbers (for share classes in this prospectus), see Additional Information.

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By exchange. You may purchase shares of a Vanguard fund using the proceeds from the simultaneous redemption of shares of another Vanguard fund. You may initiate an exchange online (if you are registered for online access), by telephone, or by mail. See

Exchanging Shares.

Trade Date

The trade date for any purchase request received in good order will depend on the day and time Vanguard receives your request, the manner in which you are paying, and the type of fund you are purchasing. Your purchase will be executed using the net asset value (NAV) as calculated on the trade date. NAVs are calculated only on days that the New York Stock Exchange (NYSE) is open for trading (a business day).

For purchases by check into all funds other than money market funds and for purchases by exchange, wire, or electronic bank transfer (not using an Automatic Investment Plan) into all funds: If the purchase request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date for the purchase will be the same day. If the purchase request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date for the purchase will be the next business day.

For purchases by check into money market funds: If the purchase request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date for the purchase will be the next business day. If the purchase request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date for the purchase will be the second business day following the day Vanguard receives the purchase request. Because money market instruments must be purchased with federal funds and it takes a money market mutual fund one business day to convert check proceeds into federal funds, the trade date for the purchase will be one business day later than for other funds.

For purchases by electronic bank transfer using an Automatic Investment Plan: Your trade date generally will be the date you selected for withdrawal of funds from your designated bank account. Your bank account generally will be debited on the business day after your trade date. If the date you selected for withdrawal of funds from your bank account falls on a weekend, holiday, or other nonbusiness day, your trade date generally will be the previous business day. For retirement accounts, if the date you selected for withdrawal of funds from your designated bank account falls on the last business day of the year, your trade date will be the first business day of the following year. Please note that if you select the first of the month for automated withdrawals from your designated bank account, trades designated for January 1 will receive the next business day’s trade date.

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If your purchase request is not accurate and complete, it may be rejected. See Other Rules You Should Know—Good Order.

For further information about purchase transactions, consult our website at vanguard.com or see Contacting Vanguard.

Other Purchase Rules You Should Know

Admiral Shares. Admiral Shares generally are not available for SIMPLE IRAs, Vanguard Individual 401(k) Plans, and Vanguard retail-serviced Individual 403(b)(7) Custodial Accounts.

Check purchases. All purchase checks must be written in U.S. dollars and must be drawn on a U.S. bank. Vanguard does not accept cash, traveler’s checks, or money orders. In addition, Vanguard may refuse “starter checks” and checks that are not made payable to Vanguard.

New accounts. We are required by law to obtain from you certain personal information that we will use to verify your identity. If you do not provide the information, we may not be able to open your account. If we are unable to verify your identity, Vanguard reserves the right, without notice, to close your account or take such other steps as we deem reasonable. Certain types of accounts may require additional documentation.

Refused or rejected purchase requests. Vanguard reserves the right to stop selling fund shares or to reject any purchase request at any time and without notice, including, but not limited to, purchases requested by exchange from another Vanguard fund. This also includes the right to reject any purchase request because the investor has a history of frequent trading or because the purchase may negatively affect a fund’s operation or performance.

Large purchases. Call Vanguard before attempting to invest a large dollar amount.

No cancellations. Vanguard will not accept your request to cancel any purchase request once processing has begun. Please be careful when placing a purchase request.

Converting Shares

When a conversion occurs, you receive shares of one class in place of shares of another class of the same fund. At the time of conversion, the dollar value of the “new” shares you receive equals the dollar value of the “old” shares that were converted. In other words, the conversion has no effect on the value of your investment in the fund at the time of the conversion. However, the number of shares you own after the conversion may be greater than or less than the number of shares you owned before the conversion, depending on the NAVs of the two share classes.

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Vanguard will not accept your request to cancel any self-directed conversion request once processing has begun. Please be careful when placing a conversion request.

A conversion between share classes of the same fund is a nontaxable event.

Trade Date

The trade date for any conversion request received in good order will depend on the day and time Vanguard receives your request. Your conversion will be executed using the NAVs of the different share classes on the trade date. NAVs are calculated only on days that the NYSE is open for trading (a business day).

For a conversion request (other than a request to convert to ETF Shares) received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date will be the same day. For a conversion request received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date will be the next business day. See Other Rules You Should Know.

Conversions From Investor Shares to Admiral Shares

Self-directed conversions. If your account balance in the Fund is at least $10,000, you may ask Vanguard to convert your Investor Shares to Admiral Shares. You may request a conversion through our website (if you are registered for online access), by telephone, or by mail. Institutional, financial intermediary, and Vanguard retail managed clients should contact Vanguard for information on special eligibility rules that may apply to them. See Contacting Vanguard.

Automatic conversions. Vanguard conducts periodic reviews of account balances and may, if your account balance in the Fund exceeds $10,000, automatically convert your Investor Shares to Admiral Shares. You will be notified before an automatic conversion occurs and will have an opportunity to instruct Vanguard not to effect the conversion. Institutional, financial intermediary, and Vanguard retail managed clients should contact Vanguard for information on special eligibility rules that may apply to them.

Conversions to Institutional Shares

You are eligible for a self-directed conversion from another share class to Institutional Shares of the Fund, provided that your account meets all Institutional Shares’ eligibility requirements. You may request a conversion through our website (if you are registered for online access), or you may contact Vanguard by telephone or by mail to request this transaction. Accounts that qualify for Institutional Shares will not be automatically converted.

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Conversions to ETF Shares

Owners of conventional shares (i.e., not exchange-traded shares) issued by the Fund may convert those shares to ETF Shares of equivalent value of the same fund. Please note that investors who own conventional shares through a 401(k) plan or other employer-sponsored retirement or benefit plan generally may not convert those shares to ETF Shares and should check with their plan sponsor or recordkeeper. ETF Shares, whether acquired through a conversion or purchased on the secondary market, cannot be converted to conventional shares by a shareholder. Also, ETF Shares of one fund cannot be exchanged for ETF Shares of another fund.

ETF Shares must be held in a brokerage account. Thus, before converting conventional shares to ETF Shares, you must have an existing, or open a new, brokerage account. This account may be with Vanguard Brokerage Services^® (Vanguard Brokerage) or with any other brokerage firm.

Vanguard Brokerage does not impose a fee on conversions from conventional shares to Vanguard ETF Shares. However, other brokerage firms may charge a fee to process a conversion. Vanguard reserves the right, in the future, to impose a transaction fee on conversions or to limit or terminate the conversion privilege. For additional information on converting conventional shares to ETF Shares, please contact Vanguard to obtain a prospectus for ETF Shares. See Contacting Vanguard.

Mandatory Conversions to Another Share Class

If an account no longer meets the balance requirements for a share class, Vanguard may automatically convert the shares in the account to another share class, as appropriate. A decline in the account balance because of market movement may result in such a conversion. Vanguard will notify the investor in writing before any mandatory conversion occurs.

Redeeming Shares

How to Initiate a Redemption Request

Be sure to check Exchanging Shares, Frequent-Trading Limitations, and Other Rules You Should Know before placing your redemption request.

Online. You may request a redemption of shares or request an exchange through our website or our mobile application if you are registered for online access.

By telephone. You may call Vanguard to request a redemption of shares or an exchange. See Contacting Vanguard.

By mail. You may send a written request to Vanguard to redeem from a fund account or to make an exchange. See Contacting Vanguard.

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How to Receive Redemption Proceeds

By electronic bank transfer. You may have the proceeds of a fund redemption sent directly to a designated bank account. To establish the electronic bank transfer service on an account, you must designate a bank account online, complete a special form, or fill out the appropriate section of your account registration form. After the service is set up on your account, you can redeem shares by electronic bank transfer on a regular schedule (Automatic Withdrawal Plan) or upon request. Your redemption request can be initiated online (if you are registered for online access), by telephone, or by mail.

By wire. To receive your proceeds by wire, you may instruct Vanguard to wire your redemption proceeds ($100 minimum) to a previously designated bank account. To establish the wire redemption service, you generally must designate a bank account online, complete a special form, or fill out the appropriate section of your account registration form.

By exchange. You may have the proceeds of a Vanguard fund redemption invested directly in shares of another Vanguard fund. You may initiate an exchange online (if you are registered for online access), by telephone, or by mail. See Exchanging Shares.

By check. If you have not chosen another redemption method, Vanguard will mail you a redemption check, generally payable to all registered account owners, normally within two business days of your trade date, and generally to the address of record.

Trade Date

The trade date for any redemption request received in good order will depend on the day and time Vanguard receives your request and the manner in which you are redeeming. Your redemption will be executed using the NAV as calculated on the trade date. NAVs are calculated only on days that the NYSE is open for trading (a business day).

For redemptions by check, exchange, or wire: If the redemption request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date will be the same day. If the redemption request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date will be the next business day.

• Note on timing of wire redemptions from money market funds: For telephone requests received by Vanguard on a business day before 10:45 a.m., Eastern time (2 p.m., Eastern time, for Vanguard Prime Money Market Fund; 12:30 p.m., Eastern time, for Vanguard Federal Money Market Fund), the redemption proceeds generally will leave Vanguard by the close of business the same day. For telephone requests received by Vanguard on a business day after those cut-off times, or on a nonbusiness day, and for all requests other than by telephone, the redemption

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proceeds generally will leave Vanguard by the close of business on the next business day.

• Note on timing of wire redemptions from all other funds: For requests received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the redemption proceeds generally will leave Vanguard by the close of business on the next business day. For requests received by Vanguard on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the redemption proceeds generally will leave Vanguard by the close of business on the second business day after Vanguard receives the request.

For redemptions by electronic bank transfer using an Automatic Withdrawal Plan: Your trade date generally will be the date you selected for withdrawal of funds (redemption of shares) from your Vanguard account. Proceeds of redeemed shares generally will be credited to your designated bank account two business days after your trade date. If the date you selected for withdrawal of funds from your Vanguard account falls on a weekend, holiday, or other nonbusiness day, your trade date generally will be the previous business day. For retirement accounts, if the date you selected for withdrawal of funds from your Vanguard account falls on the last day of the year and if that date is a holiday, your trade date will be the first business day of the following year. Please note that if you designate the first of the month for automated withdrawals, trades designated for January 1 will receive the next business day’s trade date.

For redemptions by electronic bank transfer not using an Automatic Withdrawal Plan: If the redemption request is received by Vanguard on a business day before the close of regular trading on the NYSE (generally 4 p.m., Eastern time), the trade date will be the same day. If the redemption request is received on a business day after the close of regular trading on the NYSE, or on a nonbusiness day, the trade date will be the next business day.

If your redemption request is not accurate and complete, it may be rejected. If we are unable to send your redemption proceeds by wire or electronic bank transfer because the receiving institution rejects the transfer, Vanguard will make additional efforts to complete your transaction. If Vanguard is still unable to complete the transaction, we may send the proceeds of the redemption to you by check, generally payable to all registered account owners, or use your proceeds to purchase new shares of the fund from which you sold shares for the purpose of the wire or electronic bank transfer transaction. See Other Rules You Should Know—Good Order.

If your redemption request is received in good order, we typically expect that redemption proceeds will be paid by the Fund within one business day of the trade date; however, in certain circumstances, investors may experience a longer

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settlement period at the time of the transaction. For further information, see “Potentially disruptive redemptions” and “Emergency circumstances.”

For further information about redemption transactions, consult our website at vanguard.com or see Contacting Vanguard.

Other Redemption Rules You Should Know

Documentation for certain accounts. Special documentation may be required to redeem from certain types of accounts, such as trust, corporate, nonprofit, or retirement accounts. Please call us before attempting to redeem from these types of accounts.

Potentially disruptive redemptions. Vanguard reserves the right to pay all or part of a redemption in kind—that is, in the form of securities—if we reasonably believe that a cash redemption would negatively affect the fund’s operation or performance or that the shareholder may be engaged in market-timing or frequent trading. Under these circumstances, Vanguard also reserves the right to delay payment of the redemption proceeds for up to seven calendar days. By calling us before you attempt to redeem a large dollar amount, you may avoid in-kind or delayed payment of your redemption. Please see Frequent-Trading Limitations for information about Vanguard’s policies to limit frequent trading.

Recently purchased shares. Although you can redeem shares at any time, proceeds may not be made available to you until the fund collects payment for your purchase. This may take up to seven calendar days for shares purchased by check or by electronic bank transfer. If you have written a check on a fund with checkwriting privileges, that check may be rejected if your fund account does not have a sufficient available balance.

Address change. If you change your address online or by telephone, there may be up to a 14-day restriction on your ability to request check redemptions online and by telephone. You can request a redemption in writing at any time. Confirmations of address changes are sent to both the old and new addresses.

Payment to a different person or address. At your request, we can make your redemption check payable, or wire your redemption proceeds, to a different person or send it to a different address. However, this generally requires the written consent of all registered account owners and may require additional documentation, such as a signature guarantee or a notarized signature. You may obtain a signature guarantee from some commercial or savings banks, credit unions, trust companies, or member firms of a U.S. stock exchange.

No cancellations. Vanguard will not accept your request to cancel any redemption request once processing has begun. Please be careful when placing a redemption request.

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Emergency circumstances. Vanguard funds can postpone payment of redemption proceeds for up to seven calendar days. In addition, Vanguard funds can suspend redemptions and/or postpone payments of redemption proceeds beyond seven calendar days at times when the NYSE is closed or during emergency circumstances, as determined by the SEC.

Exchanging Shares

An exchange occurs when you use the proceeds from the redemption of shares of one Vanguard fund to simultaneously purchase shares of a different Vanguard fund. You can make exchange requests online (if you are registered for online access), by telephone, or by mail. See Purchasing Shares and Redeeming Shares.

If the NYSE is open for regular trading (generally until 4 p.m., Eastern time, on a business day) at the time an exchange request is received in good order, the trade date generally will be the same day. See Other Rules You Should Know—Good Order for additional information on all transaction requests.

Vanguard will not accept your request to cancel any exchange request once processing has begun. Please be careful when placing an exchange request.

Call Vanguard before attempting to exchange a large dollar amount. By calling us before you attempt to exchange a large dollar amount, you may avoid delayed or rejected transactions.

Please note that Vanguard reserves the right, without notice, to revise or terminate the exchange privilege, limit the amount of any exchange, or reject an exchange, at any time, for any reason. See Frequent-Trading Limitations for additional restrictions on exchanges.

Frequent-Trading Limitations

Because excessive transactions can disrupt management of a fund and increase the fund’s costs for all shareholders, the board of trustees of each Vanguard fund places certain limits on frequent trading in the funds. Each Vanguard fund (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund) limits an investor’s purchases or exchanges into a fund account for 30 calendar days after the investor has redeemed or exchanged out of that fund account. ETF Shares are not subject to these frequent-trading limits.

For Vanguard Retirement Investment Program pooled plans, the limitations apply to exchanges made online or by telephone.

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These frequent-trading limitations do not apply to the following:

• Purchases of shares with reinvested dividend or capital gains distributions.

• Transactions through Vanguard’s Automatic Investment Plan, Automatic Exchange Service, Direct Deposit Service, Automatic Withdrawal Plan, Required Minimum Distribution Service, and Vanguard Small Business Online^®.

• Discretionary transactions through Vanguard Asset Management Services^™, Vanguard Personal Advisor Services^®, and Vanguard Institutional Advisory Services^®.

• Redemptions of shares to pay fund or account fees.

• Redemptions of shares to remove excess shareholder contributions to certain types of retirement accounts (including, but not limited to, IRAs, certain Individual 403(b)(7) Custodial Accounts, and Vanguard Individual 401(k) Plans).

• Transaction requests submitted by mail to Vanguard from shareholders who hold their accounts directly with Vanguard or through a Vanguard brokerage account. (Transaction requests submitted by fax, if otherwise permitted, are subject to the limitations.)

• Transfers and reregistrations of shares within the same fund.

• Purchases of shares by asset transfer or direct rollover.

• Conversions of shares from one share class to another in the same fund.

• Checkwriting redemptions.

• Section 529 college savings plans.

• Certain approved institutional portfolios and asset allocation programs, as well as trades made by funds or trusts managed by Vanguard or its affiliates that invest in other Vanguard funds. (Please note that shareholders of Vanguard’s funds of funds are subject to the limitations.)

For participants in employer-sponsored defined contribution plans,* the frequent-trading limitations do not apply to:

• Purchases of shares with participant payroll or employer contributions or loan repayments.

• Purchases of shares with reinvested dividend or capital gains distributions.

• Distributions, loans, and in-service withdrawals from a plan.

• Redemptions of shares as part of a plan termination or at the direction of the plan.

• Transactions executed through the Vanguard Managed Account Program.

• Redemptions of shares to pay fund or account fees.

• Share or asset transfers or rollovers.

• Reregistrations of shares.

• Conversions of shares from one share class to another in the same fund.

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• Exchange requests submitted by written request to Vanguard. (Exchange requests submitted by fax, if otherwise permitted, are subject to the limitations.)

* The following Vanguard fund accounts are subject to the frequent-trading limitations: SEP-IRAs, SIMPLE IRAs, certain Individual 403(b)(7) Custodial Accounts, and Vanguard Individual 401(k) Plans.

Accounts Held by Institutions (Other Than Defined Contribution Plans)

Vanguard will systematically monitor for frequent trading in institutional clients’ accounts. If we detect suspicious trading activity, we will investigate and take appropriate action, which may include applying to a client’s accounts the 30-day policy previously described, prohibiting a client’s purchases of fund shares, and/or revoking the client’s exchange privilege.

Accounts Held by Intermediaries

When intermediaries establish accounts in Vanguard funds for the benefit of their clients, we cannot always monitor the trading activity of the individual clients. However, we review trading activity at the intermediary (omnibus) level, and if we detect suspicious activity, we will investigate and take appropriate action. If necessary, Vanguard may prohibit additional purchases of fund shares by an intermediary, including for the benefit of certain of the intermediary’s clients. Intermediaries also may monitor their clients’ trading activities with respect to Vanguard funds.

For those Vanguard funds that charge purchase and/or redemption fees, intermediaries will be asked to assess these fees on client accounts and remit these fees to the funds. The application of purchase and redemption fees and frequent-trading limitations may vary among intermediaries. There are no assurances that Vanguard will successfully identify all intermediaries or that intermediaries will properly assess purchase and redemption fees or administer frequent-trading limitations. If you invest with Vanguard through an intermediary, please read that firm’s materials carefully to learn of any other rules or fees that may apply.

Other Rules You Should Know

Prospectus and Shareholder Report Mailings

When two or more shareholders have the same last name and address, just one summary prospectus (or prospectus) and/or shareholder report may be sent in an attempt to eliminate the unnecessary expense of duplicate mailings. You may request individual prospectuses and reports by contacting our Client Services Department in writing, by telephone, or online. See Contacting Vanguard.

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Vanguard.com

Registration. If you are a registered user of vanguard.com, you can review your account holdings; buy, sell, or exchange shares of most Vanguard funds; and perform most other transactions through our website. You must register for this service online.

Electronic delivery. Vanguard can deliver your account statements, transaction confirmations, prospectuses, certain tax forms, and shareholder reports electronically. If you are a registered user of vanguard.com, you can consent to the electronic delivery of these documents by logging on and changing your mailing preferences under “Account Maintenance.” You can revoke your electronic consent at any time through our website, and we will begin to send paper copies of these documents within 30 days of receiving your revocation.

Telephone Transactions

Automatic. When we set up your account, we will automatically enable you to do business with us by telephone, unless you instruct us otherwise in writing.

Tele-Account^®. To obtain fund and account information through Vanguard’s automated telephone service, you must first establish a Personal Identification Number (PIN) by calling Tele-Account at 800-662-6273.

Proof of a caller’s authority. We reserve the right to refuse a telephone request if the caller is unable to provide the requested information or if we reasonably believe that the caller is not an individual authorized to act on the account. Before we allow a caller to act on an account, we may request the following information:

• Authorization to act on the account (as the account owner or by legal documentation or other means).

• Account registration and address.

• Fund name and account number, if applicable.

• Other information relating to the caller, the account owner, or the account.

Good Order

We reserve the right to reject any transaction instructions that are not in “good order.” Good order generally means that your instructions:

• Include the fund name and account number.

• Include the amount of the transaction (stated in dollars, shares, or percentage).

Written instructions also must generally include:

• An original signature and date from the authorized person(s).

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• Signature guarantees or notarized signatures, if required for the type of transaction.

(Call Vanguard for specific requirements.)

• Any supporting documentation that may be required.

Written instructions are acceptable when a Vanguard form is not applicable. The requirements vary among types of accounts and transactions. For more information, consult our website at vanguard.com or see Contacting Vanguard.

Vanguard reserves the right, without notice, to revise the requirements for good order.

Future Trade-Date Requests

Vanguard does not accept requests to hold a purchase, conversion, redemption, or exchange transaction for a future date. All such requests will receive trade dates as previously described in Purchasing Shares, Converting Shares, Redeeming Shares, and

Exchanging Shares. Vanguard reserves the right to return future-dated purchase checks.

Accounts With More Than One Owner

If an account has more than one owner or authorized person, Vanguard generally will accept instructions from any one owner or authorized person.

Responsibility for Fraud

Vanguard will not be responsible for any account losses because of fraud if we reasonably believe that the person transacting business on an account is authorized to do so. Please take precautions to protect yourself from fraud. Keep your account information private, and immediately review any account statements or other information that we provide to you. It is important that you contact Vanguard immediately about any transactions or changes to your account that you believe to be unauthorized.

Uncashed Checks

Please cash your distribution or redemption checks promptly. Vanguard will not pay interest on uncashed checks. Vanguard may be required to transfer assets related to uncashed checks to a state under the state’s abandoned property law.

Dormant Accounts

If your account has no activity in it for a period of time, Vanguard may be required to transfer it to a state under the state’s abandoned property law.

Unusual Circumstances

If you experience difficulty contacting Vanguard online or by telephone, you can send us your transaction request by regular or express mail. See Contacting Vanguard for addresses.

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Investing With Vanguard Through Other Firms

You may purchase or sell shares of most Vanguard funds through a financial intermediary, such as a bank, a broker, or an investment advisor. Please consult your financial intermediary to determine which, if any, shares are available through that firm and to learn about other rules that may apply. Your financial intermediary can provide you with account information and any required tax forms.

Please see Frequent-Trading Limitations—Accounts Held by Intermediaries for information about the assessment of any purchase or redemption fees and the monitoring of frequent trading for accounts held by intermediaries.

Account Service Fee

Vanguard charges a $20 account service fee on fund accounts that have a balance below $10,000 for any reason, including market fluctuation. The account service fee applies to both retirement and nonretirement fund accounts and will be assessed on fund accounts in all Vanguard funds, regardless of the account minimum. The fee, which will be collected by redeeming fund shares in the amount of $20, will be deducted from a fund account only once per calendar year.

If you register on vanguard.com and elect to receive electronic delivery of statements, reports, and other materials for all of your fund accounts, the account service fee for balances below $10,000 will not be charged, so long as that election remains in effect.

The account service fee also does not apply to the following:

• Money market sweep accounts owned in connection with a Vanguard Brokerage ^® Services account.

• Accounts held through intermediaries.

• Accounts held by institutional clients.

• Accounts held by Voyager, Voyager Select, Flagship, and Flagship Select clients.

Eligibility is based on total household assets held at Vanguard, with a minimum of $50,000 to qualify for Vanguard Voyager Services^®, $500,000 for Vanguard Voyager Select Services^®, $1 million for Vanguard Flagship Services^®, and $5 million for Vanguard Flagship Select Services^™. Vanguard determines eligibility by aggregating assets of all qualifying accounts held by the investor and immediate family members who reside at the same address. Aggregate assets include investments in Vanguard mutual funds, Vanguard ETFs^®, certain annuities through Vanguard, the Vanguard 529 Plan, and certain small-business accounts. Assets in employer-sponsored retirement plans for which Vanguard provides recordkeeping services may be included in determining eligibility if the investor also has a personal account holding Vanguard mutual funds. Note that assets held in a Vanguard Brokerage Services account (other than Vanguard funds, including Vanguard ETFs) are not included when determining a household’s eligibility.

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• Participant accounts in employer-sponsored defined contribution plans.* Please consult your enrollment materials for the rules that apply to your account.

• Section 529 college savings plans.

* The following Vanguard fund accounts have alternative fee structures: SIMPLE IRAs, certain Individual 403(b)(7) Custodial Accounts, Vanguard Retirement Investment Program pooled plans, and Vanguard Individual 401(k) Plans.

Low-Balance Accounts

The Fund reserves the right to liquidate a fund account whose balance falls below the account minimum for any reason, including market fluctuation. This liquidation policy applies to nonretirement fund accounts and accounts that are held through intermediaries. Any such liquidation will be preceded by written notice to the investor.

Right to Change Policies

In addition to the rights expressly stated elsewhere in this prospectus, Vanguard reserves the right, without notice, to (1) alter, add, or discontinue any conditions of purchase (including eligibility requirements), redemption, exchange, conversion, service, or privilege at any time; (2) accept initial purchases by telephone; (3) freeze any account and/or suspend account services if Vanguard has received reasonable notice of a dispute regarding the assets in an account, including notice of a dispute between the registered or beneficial account owners, or if Vanguard reasonably believes a fraudulent transaction may occur or has occurred; (4) temporarily freeze any account and/or suspend account services upon initial notification to Vanguard of the death of the shareholder until Vanguard receives required documentation in good order; (5) alter, impose, discontinue, or waive any purchase fee, redemption fee, account service fee, or other fees charged to a shareholder or a group of shareholders; and (6) redeem an account or suspend account privileges, without the owner’s permission to do so, in cases of threatening conduct or activity Vanguard believes to be suspicious, fraudulent, or illegal. Changes may affect any or all investors. These actions will be taken when, at the sole discretion of Vanguard management, Vanguard reasonably believes they are in the best interest of a fund.

Share Classes

Vanguard reserves the right, without notice, to change the eligibility requirements of its share classes, including the types of clients who are eligible to purchase each share class.

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Fund and Account Updates

Confirmation Statements

We will send (or provide through our website, whichever you prefer) a confirmation of your trade date and the amount of your transaction when you buy, sell, exchange, or convert shares. However, we will not send confirmations reflecting only checkwriting redemptions or the reinvestment of dividend or capital gains distributions. For any month in which you had a checkwriting redemption, a Checkwriting Activity Statement will be sent to you itemizing the checkwriting redemptions for that month. Promptly review each confirmation statement that we provide to you. It is important that you contact Vanguard immediately with any questions you may have about any transaction reflected on a confirmation statement, or Vanguard will consider the transaction properly processed.

Portfolio Summaries

We will send (or provide through our website, whichever you prefer) quarterly portfolio summaries to help you keep track of your accounts throughout the year. If you prefer, you may request to receive monthly portfolio summaries. Each summary shows the market value of your account at the close of the statement period, as well as all distributions, purchases, redemptions, exchanges, transfers, and conversions for the current calendar quarter (or month). Promptly review each summary that we provide to you. It is important that you contact Vanguard immediately with any questions you may have about any transaction reflected on the summary, or Vanguard will consider the transaction properly processed.

Tax Information Statements

For most accounts, Vanguard (or your intermediary) is required to provide annual tax forms to assist you in preparing your income tax returns. These forms are generally available for each calendar year early in the following year. Registered users of vanguard.com can also view certain forms through our website. Vanguard (or your intermediary) may also provide you with additional tax-related documentation. For more information, consult our website at vanguard.com or see Contacting Vanguard.

Annual and Semiannual Reports

We will send (or provide through our website, whichever you prefer) reports about Vanguard REIT Index Fund twice a year, in March and September. These reports include overviews of the financial markets and provide the following specific Fund information:

• Performance assessments and comparisons with industry benchmarks.

• Financial statements with listings of Fund holdings.

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Portfolio Holdings

Please consult the Fund‘s Statement of Additional Information or our website for a description of the policies and procedures that govern disclosure of the Fund’s portfolio holdings.

Employer-Sponsored Plans

Your plan administrator or your employee benefits office can provide you with detailed information on how to participate in your plan and how to elect the Fund as an investment option.

• If you have any questions about the Fund or Vanguard, including those about the Fund’s investment objective, strategies, or risks, contact Vanguard Participant Services toll-free at 800-523-1188 or visit our website at vanguard.com.

• If you have questions about your account, contact your plan administrator or the organization that provides recordkeeping services for your plan.

• Be sure to carefully read each topic that pertains to your transactions with Vanguard.

Vanguard reserves the right to change its policies without notice to shareholders.

Transactions

Processing times for your transaction requests may differ among recordkeepers or among transaction and funding types. Your plan’s recordkeeper (which may also be Vanguard) will determine the necessary processing time frames for your transaction requests prior to submission to the Fund. Consult your recordkeeper or plan administrator for more information.

If Vanguard is serving as your plan recordkeeper and if your transaction involves one or more investments with an early cut-off time for processing or another trading restriction, your entire transaction will be subject to the restriction when the trade date for your transaction is determined.

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Vanguard Addresses

Please be sure to use the correct address. Use of an incorrect address could delay the processing of your transaction.

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THIS FUND IS NOT SPONSORED, ENDORSED, SOLD OR PROMOTED BY MSCI INC. (“MSCI”), ANY OF ITS AFFILIATES, ANY OF ITS DIRECT OR INDIRECT INFORMATION PROVIDERS OR ANY OTHER THIRD PARTY INVOLVED IN, OR RELATED TO, COMPILING, COMPUTING OR CREATING ANY MSCI INDEX (COLLECTIVELY, THE “MSCI PARTIES”). THE MSCI INDEXES ARE THE EXCLUSIVE PROPERTY OF MSCI. MSCI AND THE MSCI INDEX NAMES ARE SERVICE MARK(S) OF MSCI OR ITS AFFILIATES AND HAVE BEEN LICENSED FOR USE FOR CERTAIN PURPOSES BY VANGUARD. NONE OF THE MSCI PARTIES MAKES ANY REPRESENTATION OR WARRANTY, EXPRESS OR IMPLIED, TO THE OWNERS OF THIS FUND OR ANY MEMBER OF THE PUBLIC REGARDING THE ADVISABILITY OF INVESTING IN FUNDS GENERALLY OR IN THIS FUND PARTICULARLY OR THE ABILITY OF ANY MSCI INDEX TO TRACK CORRESPONDING STOCK MARKET PERFORMANCE. MSCI OR ITS AFFILIATES ARE THE LICENSORS OF CERTAIN TRADEMARKS, SERVICE MARKS AND TRADE NAMES AND OF THE MSCI INDEXES WHICH ARE DETERMINED, COMPOSED AND CALCULATED BY MSCI WITHOUT REGARD TO THIS FUND OR THE ISSUER OR OWNER OF THIS FUND. NONE OF THE MSCI PARTIES HAS ANY OBLIGATION TO TAKE THE NEEDS OF THE ISSUERS OR OWNERS OF THIS FUND INTO CONSIDERATION IN DETERMINING, COMPOSING OR CALCULATING THE MSCI INDEXES. NONE OF THE MSCI PARTIES IS RESPONSIBLE FOR OR HAS PARTICIPATED IN THE DETERMINATION OF THE TIMING OF, PRICES AT, OR QUANTITIES OF THIS FUND TO BE ISSUED OR IN THE DETERMINATION OR CALCULATION OF THE CONSIDERATION INTO WHICH THIS FUND IS REDEEMABLE. NONE OF THE MSCI PARTIES HAS ANY OBLIGATION OR LIABILITY TO THE OWNERS OF THIS FUND IN CONNECTION WITH THE ADMINISTRATION, MARKETING OR OFFERING OF THIS FUND.

ALTHOUGH MSCI SHALL OBTAIN INFORMATION FOR INCLUSION IN OR FOR USE IN THE CALCULATION OF THE MSCI INDEXES FROM SOURCES WHICH MSCI CONSIDERS RELIABLE, NONE OF THE MSCI PARTIES WARRANTS OR GUARANTEES THE ORIGINALITY, ACCURACY AND/OR THE COMPLETENESS OF ANY MSCI INDEX OR ANY DATA INCLUDED THEREIN. NONE OF THE MSCI PARTIES MAKES ANY WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY LICENSEE, LICENSEE’S CUSTOMERS OR COUNTERPARTIES, ISSUERS OF THE FUNDS, OWNERS OF THE FUNDS, OR ANY OTHER PERSON OR ENTITY, FROM THE USE OF ANY MSCI INDEX OR ANY DATA INCLUDED THEREIN IN CONNECTION WITH THE RIGHTS LICENSED HEREUNDER OR FOR ANY OTHER USE. NONE OF THE MSCI PARTIES SHALL HAVE ANY LIABILITY FOR ANY ERRORS, OMISSIONS OR INTERRUPTIONS OF OR IN CONNECTION WITH ANY MSCI INDEX OR ANY DATA INCLUDED THEREIN. FURTHER, NONE OF THE MSCI PARTIES MAKES ANY EXPRESS OR IMPLIED WARRANTIES OF ANY KIND, AND THE MSCI PARTIES HEREBY EXPRESSLY DISCLAIM ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, WITH RESPECT TO ANY MSCI INDEX AND ANY DATA INCLUDED THEREIN. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT SHALL ANY OF THE MSCI PARTIES HAVE ANY LIABILITY FOR ANY DIRECT, INDIRECT, SPECIAL, PUNITIVE, CONSEQUENTIAL OR ANY OTHER DAMAGES (INCLUDING WITHOUT LIMITATION LOST PROFITS) EVEN IF NOTIFIED OF THE POSSIBILITY OF SUCH DAMAGES.

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Glossary of Investment Terms

Active Management. An investment approach that seeks to exceed the average returns of a particular financial market or market segment. In selecting securities to buy and sell, active managers may rely on, among other things, research, market forecasts, quantitative models, and their own judgment and experience.

Capital Gains Distribution. Payment to mutual fund shareholders of gains realized on securities that a fund has sold at a profit, minus any realized losses.

Common Stock. A security representing ownership rights in a corporation.

Cost Basis. The adjusted cost of an investment, used to determine a capital gain or loss for tax purposes.

Distributions. Payments to mutual fund shareholders of dividend income, capital gains, and return of capital generated by the fund’s investment activities and distribution policies, after expenses.

Dividend Distribution. Payment to mutual fund shareholders of income from interest or dividends generated by a fund’s investments.

Expense Ratio. A fund’s total annual operating expenses expressed as a percentage of the fund’s average net assets. The expense ratio includes management and administrative expenses, but it does not include the transaction costs of buying and selling portfolio securities.

Inception Date. The date on which the assets of a fund (or one of its share classes) are first invested in accordance with the fund’s investment objective. For funds with a subscription period, the inception date is the day after that period ends. Investment performance is generally measured from the inception date.

Indexing. A low-cost investment strategy in which a mutual fund attempts to track—rather than outperform—a specified market benchmark, or “index.”

Joint Committed Credit Facility. The Fund and certain other funds managed by Vanguard participate in a committed credit facility provided by a syndicate of lenders pursuant to a credit agreement that may be renewed annually; each fund is individually liable for its borrowings, if any, under the credit facility. The amount and terms of the committed credit facility are subject to approval by the fund’s board of trustees and renegotiation with the lender syndicate on an annual basis.

Liquidity. The degree of a security’s marketability (i.e., how quickly the security can be sold at a fair price and converted to cash).

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Median Market Capitalization. An indicator of the size of companies in which a fund invests; the midpoint of market capitalization (market price x shares outstanding) of a fund’s stocks, weighted by the proportion of the fund’s assets invested in each stock. Stocks representing half of the fund’s assets have market capitalizations above the median, and the rest are below it.

Mutual Fund. An investment company that pools the money of many people and invests it in a variety of securities in an effort to achieve a specific objective over time.

New York Stock Exchange (NYSE). A stock exchange based in New York City that is open for regular trading on business days, Monday through Friday, from 9:30 a.m. to 4 p.m., Eastern time. Net asset values (NAVs) are calculated each business day as of the close of regular trading on the NYSE. In the rare event the NYSE experiences unanticipated trade disruptions and is unavailable at the close of the trading day, NAVs will be calculated as of the close of regular trading on the Nasdaq (or another alternate exchange if the Nasdaq is unavailable), generally 4 p.m., Eastern time.

Return of Capital. A return of all or part of your original investment in a fund. In general, return of capital reduces your cost basis in a fund’s shares and is not taxable to you until your cost basis has been reduced to zero.

Securities. Stocks, bonds, money market instruments, and other investments.

Total Return. A percentage change, over a specified time period, in a mutual fund’s net asset value, assuming the reinvestment of all distributions of dividends and capital gains.

Tracking Error. A measure of the difference between the performance of a fund or portfolio and that of its benchmark index.

Volatility. The fluctuations in value of a mutual fund or other security. The greater a fund’s volatility, the wider the fluctuations in its returns.

Wholly Owned Subsidiary. A company of which 95% or more of the outstanding voting securities are owned by another company, as defined by the Investment Company Act of 1940.

Yield. Income (interest or dividends) earned by an investment, expressed as a percentage of the investment’s price.

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Connect with Vanguard^® > vanguard.com

For More Information

If you would like more information about Vanguard REIT Index Fund, the following documents are available free upon request:

Annual/Semiannual Reports to Shareholders

Additional information about the Fund’s investments is available in the Fund’s annual and semiannual reports to shareholders. In the annual report, you will find a discussion of the market conditions and investment strategies that significantly affected the Fund’s performance during its last fiscal year.

Statement of Additional Information (SAI)

The SAI provides more detailed information about the Fund and is incorporated by reference into (and thus legally a part of) this prospectus.

To receive a free copy of the latest annual or semiannual report or the SAI, or to request additional information about the Fund or other Vanguard funds, please visit vanguard.com or contact us as follows:

If you are an individual investor:

The Vanguard Group

Investor Information Department P.O. Box 2600 Valley Forge, PA 19482-2600 Telephone: 800-662-7447

Text telephone for people with hearing impairment: 800-749-7273

If you are a participant in an employer-sponsored plan:

The Vanguard Group Participant Services P.O. Box 2900 Valley Forge, PA 19482-2900 Telephone: 800-523-1188

Text telephone for people with hearing impairment: 800-749-7273

If you are a current Vanguard shareholder and would like information about your account, account transactions, and/or account statements, please call:

Client Services Department Telephone: 800-662-2739

Text telephone for people with hearing impairment: 800-749-7273

Information Provided by the Securities and Exchange Commission (SEC)

You can review and copy information about the Fund (including the SAI) at the SEC’s Public Reference Room in Washington, DC. To find out more about this public service, call the SEC at 202-551-8090. Reports and other information about the Fund are also available in the EDGAR database on the SEC’s website at www.sec.gov, or you can receive copies of this information, for a fee, by electronic request at the following email address: [email protected], or by writing the Public Reference Section, Securities and Exchange Commission, Washington, DC 20549-1520.

Fund’s Investment Company Act file number: 811-03916

© 2017 The Vanguard Group, Inc. All rights reserved. Vanguard Marketing Corporation, Distributor.

P 123 092017

ETF Summary

Investment Objective

The Fund seeks to provide a high level of income and moderate long-term capital appreciation by tracking the performance of a benchmark index that measures the performance of publicly traded equity REITs.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold ETF Shares of the Fund.

1

Example

The following example is intended to help you compare the cost of investing in the Fund’s ETF Shares with the cost of investing in other funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the shares provide a return of 5% each year and that total annual fund operating expenses remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

This example does not include the brokerage commissions that you may pay to buy and sell Shares of the Fund.

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 7% of the average value of its portfolio.

Principal Investment Strategies

The Fund employs an indexing investment approach designed to track the performance of the MSCI US REIT Index. The Index is composed of stocks of publicly traded equity real estate investment trusts (known as REITs). The Fund attempts to replicate the Index by investing all, or substantially all, of its assets—either directly or indirectly through a wholly owned subsidiary (the underlying fund), which is itself a registered investment company—in the stocks that make up the Index, holding each stock in approximately the same proportion as its weighting in the Index. The Fund may invest a portion of its assets in the underlying fund.

2

Principal Risks

An investment in the Fund could lose money over short or even long periods. You should expect the Fund’s share price and total return to fluctuate within a wide range. The Fund is subject to the following risks, which could affect the Fund’s performance:

• Industry concentration risk, which is the chance that the stocks of REITs will decline because of adverse developments affecting the real estate industry and real property values. Because the Fund concentrates its assets in REIT stocks, industry concentration risk is high.

• Stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund’s target index may, at times, become focused in stocks of a limited number of companies, which could cause the Fund to underperform the overall stock market.

• Interest rate risk, which is the chance that REIT stock prices overall will decline and that the cost of borrowing for REITs will increase because of rising interest rates. Interest rate risk is high for the Fund.

• Investment style risk, which is the chance that the returns from REIT stocks—which typically are small- or mid-capitalization stocks—will trail returns from the overall stock market. Historically, REIT stocks have performed quite differently from the overall market.

• Asset concentration risk, which is the chance that, because the Fund’s target index (and therefore the Fund) tends to be heavily weighted in its ten largest holdings, the Fund’s performance may be hurt disproportionately by the poor performance of relatively few stocks.

Because ETF Shares are traded on an exchange, they are subject to additional risks:

• The Fund’s ETF Shares are listed for trading on NYSE Arca and are bought and sold on the secondary market at market prices. Although it is expected that the market price of an ETF Share typically will approximate its net asset value (NAV), there may be times when the market price and the NAV differ significantly. Thus, you may pay more or less than NAV when you buy ETF Shares on the secondary market, and you may receive more or less than NAV when you sell those shares.

• Although the Fund’s ETF Shares are listed for trading on NYSE Arca, it is possible that an active trading market may not be maintained.

• Trading of the Fund’s ETF Shares may be halted by the activation of individual or marketwide trading halts (which halt trading for a specific period of time when the price of a particular security or overall market prices decline by a specified percentage). Trading of the Fund’s ETF Shares may also be halted if (1) the shares are delisted from NYSE Arca without first being listed on another exchange or (2) NYSE Arca officials determine that such action is appropriate in the interest of a fair and orderly market or for the protection of investors.

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An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund‘s ETF Shares (based on NAV) has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the ETF Shares compare with those of the Fund‘s target index and a comparative index, which have investment characteristics similar to those of the Fund. The REIT Spliced Index reflects performance of the MSCI US REIT Index adjusted to include a 2% cash position (Lipper Money Market Average) through April 30, 2009, and the MSCI US REIT Index thereafter. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard REIT Index Fund ETF Shares¹

1 The year-to-date return as of the most recent calendar quarter, which ended on June 30, 2017, was 2.59%.

During the periods shown in the bar chart, the highest return for a calendar quarter was 34.63% (quarter ended September 30, 2009), and the lowest return for a quarter was –38.14% (quarter ended December 31, 2008).

4

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

Investment Advisor

The Vanguard Group, Inc. (Vanguard)

Portfolio Managers

Walter Nejman, Portfolio Manager at Vanguard. He has co-managed the Fund since 2016.

Gerard C. O’Reilly, Principal of Vanguard. He has managed the Fund since its inception in 1996 (co-managed since 2016).

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Purchase and Sale of Fund Shares

You can buy and sell ETF Shares of the Fund through a brokerage firm. The price you pay or receive for ETF Shares will be the prevailing market price, which may be more or less than the NAV of the shares. The brokerage firm may charge you a commission to execute the transaction. Unless imposed by your brokerage firm, there is no minimum dollar amount you must invest and no minimum number of shares you must buy. ETF Shares of the Fund cannot be directly purchased from or redeemed with the Fund, except by certain authorized broker-dealers. These broker-dealers may purchase and redeem ETF Shares only in large blocks (Creation Units) worth several million dollars, typically in exchange for baskets of securities. For this Fund, the number of ETF Shares in a Creation Unit is 100,000.

Tax Information

The Fund’s distributions may be taxable as ordinary income or capital gain or may constitute non–taxable return of capital. If you are investing through a tax-advantaged account, such as IRA or an employer-sponsored retirement or savings plan, special tax rules apply.

Payments to Financial Intermediaries

The Fund and its investment advisor do not pay financial intermediaries for sales of Fund shares.

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Investing in Vanguard ETF^® Shares

What Are Vanguard ETF Shares?

Vanguard ETF Shares are an exchange-traded class of shares issued by certain Vanguard mutual funds. ETF Shares represent an interest in the portfolio of stocks or bonds held by the issuing fund. This prospectus describes REIT ETF, a class of shares issued by Vanguard REIT Index Fund. In addition to ETF Shares, the Fund offers three conventional (not exchange-traded) classes of shares. This prospectus, however, relates only to ETF Shares.

How Are Vanguard ETF Shares Different From Conventional Mutual Fund Shares?

Conventional mutual fund shares can be directly purchased from and redeemed with the issuing fund for cash at the net asset value (NAV), typically calculated once a day. ETF Shares, by contrast, cannot be purchased directly from or redeemed directly with the issuing fund by an individual investor. Rather, ETF Shares can only be purchased or redeemed directly from the issuing fund by certain authorized broker-dealers. These broker-dealers may purchase and redeem ETF Shares only in large blocks (Creation Units) worth several million dollars, usually in exchange for baskets of securities and not for cash (although some funds issue and redeem Creation Units in exchange for cash or a combination of cash and securities).

An organized secondary trading market is expected to exist for ETF Shares, unlike conventional mutual fund shares, because ETF Shares are listed for trading on a national securities exchange. Individual investors can purchase and sell ETF Shares on the secondary market through a broker. Secondary-market transactions occur not at NAV, but at market prices that change throughout the day based on the supply of and demand for ETF Shares and on changes in the prices of the fund’s portfolio holdings.

The market price of a fund’s ETF Shares typically will differ somewhat from the NAV of those shares. The difference between market price and NAV is expected to be small most of the time, but in times of market disruption or extreme market volatility, the difference may become significant.

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How Do I Buy and Sell Vanguard ETF Shares?

ETF Shares of the Fund are listed for trading on NYSE Arca. You can buy and sell ETF Shares on the secondary market in the same way you buy and sell any other exchange-traded security—through a broker. Your broker may charge a commission to execute a transaction. You will also incur the cost of the “bid-ask spread,” which is the difference between the price a dealer will pay for a security and the somewhat higher price at which the dealer will sell the same security. Because secondary-market transactions occur at market prices, you may pay more (premium) or less (discount) than NAV when you buy ETF Shares and receive more or less than NAV when you sell those shares. In times of severe market disruption, the bid-ask spread and premiums/ discounts can increase significantly. Unless imposed by your broker, there is no minimum dollar amount you must invest and no minimum number of ETF Shares you must buy.

Your ownership of ETF Shares will be shown on the records of the broker through which you hold the shares. Vanguard will not have any record of your ownership. Your account information will be maintained by your broker, which will provide you with account statements, confirmations of your purchases and sales of ETF Shares, and tax information. Your broker also will be responsible for ensuring that you receive income, return of capital, and capital gains distributions, as well as shareholder reports and other communications from the fund whose ETF Shares you own. You will receive other services (e.g., dividend reinvestment and average cost information) only if your broker offers these services.

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Investing in Index Funds

What Is Indexing?

Indexing is an investment strategy for tracking the performance of a specified market benchmark, or “index.” An index is a group of securities whose overall performance is used as a standard to measure the investment performance of a particular market. There are many types of indexes. Some represent entire markets—such as the U.S. stock market or the U.S. bond market. Other indexes cover market segments—such as small-capitalization stocks or short-term bonds. The index sponsor determines the securities to include in the index, the weighting of each security in the index, and the appropriate time to make changes to the composition of the index. One cannot invest directly in an index.

An index fund holds all, or a representative sample, of the securities that make up its target index. Index funds attempt to mirror the performance of the target index, for better or worse. However, an index fund generally does not perform exactly like its target index. For example, index funds have operating expenses and transaction costs. Market indexes do not, and therefore they will usually have a slight performance advantage over funds that track them.

Index funds typically have the following characteristics:

• Variety of investments. Most Vanguard index funds generally invest in the securities of a variety of companies and industries.

• Relative performance consistency. Because they seek to track market benchmarks, index funds usually do not perform dramatically better or worse than their benchmarks.

• Low cost. Index funds are inexpensive to run compared with actively managed funds.

They have low or no research costs and typically keep trading activity—and thus brokerage commissions and other transaction costs—to a minimum compared with actively managed funds.

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More on the Fund and ETF Shares

This prospectus describes the principal risks you would face as a Fund shareholder. It is important to keep in mind one of the main axioms of investing: generally, the higher the risk of losing money, the higher the potential reward. The reverse, also, is generally true: the lower the risk, the lower the potential reward. As you consider an investment in any mutual fund, you should take into account your personal tolerance for fluctuations in the securities markets. Look for this symbol throughout the prospectus. It is used to mark detailed information about the more significant risks that you would confront as a Fund shareholder. To highlight terms and concepts important to mutual fund investors, we have provided Plain Talk^® explanations along the way. Reading the prospectus will help you decide whether the Fund is the right investment for you. We suggest that you keep this prospectus for future reference.

Share Class Overview

This prospectus offers the Fund‘s ETF Shares, an exchange-traded class of shares. A separate prospectus offers the Fund‘s Investor Shares and Admiral^TM Shares, which generally have investment minimums of $3,000 and $10,000, respectively. In addition, another prospectus offers the Fund‘s Institutional Shares, which are generally for investors who invest a minimum of $5 million.

All share classes offered by the Fund have the same investment objective, strategies, and policies. However, different share classes have different expenses; as a result, their investment performances will differ.

A Similar But Different Fund

The Fund offered by this prospectus should not be confused with Vanguard REIT II Index Fund, a separate Vanguard fund that also seeks to track the performance of the MSCI US REIT Index and is anticipated to be the underlying fund. Both funds seek to replicate the stocks that make up the target index. This index replication strategy, combined with differences in the funds’ respective cash flows and expenses, is expected to produce slightly different investment performance by the funds. To obtain a prospectus for Vanguard REIT II Index Fund, institutional investors may call Vanguard’s Institutional Division at 888-809-8102 or may call their relationship managers directly.

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A Note to Investors

Vanguard ETF Shares can be purchased directly from the issuing Fund only by authorized broker-dealers in exchange for a basket of securities (or, in some cases, for cash or a combination of cash and securities) that is expected to be worth several million dollars. Most individual investors, therefore, will not be able to purchase ETF Shares directly from the Fund. Instead, these investors will purchase ETF Shares on the secondary market with the assistance of a broker.

The following sections explain the principal investment strategies and policies that the Fund uses in pursuit of its objective. The Fund‘s board of trustees, which oversees the Fund’s management, may change investment strategies or policies in the interest of shareholders without a shareholder vote, unless those strategies or policies are designated as fundamental. Under normal circumstances, the Fund will invest at least 80% of its assets in the stocks that make up its target index. This policy may be changed only upon 60 days‘ notice to shareholders.

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Market Exposure

The Fund invests in stocks of publicly traded equity real estate investment trusts.

The Fund is subject to investment style risk, which is the chance that returns from REIT stocks—which typically are small- or mid-capitalization stocks—will trail returns from the overall stock market. Historically, REIT stocks have performed quite differently from the overall market.

Stocks of publicly traded companies and funds that invest in stocks are often classified according to market value, or market capitalization. These classifications typically include small-cap, mid-cap, and large-cap. It is important to understand that market capitalization ranges change over time. Also, interpretations of size vary, and there are no “official” definitions of small-, mid-, and large-cap, even among Vanguard fund advisors. REITs in the MSCI US REIT Index tend to be small- and mid-cap stocks. The asset-weighted median market capitalization of the Fund’s stock holdings as of January 31, 2017, was $10 billion.

Small- and mid-cap stocks tend to have greater volatility than large-cap stocks because, among other things, smaller companies often have fewer customers, financial resources, and products than larger firms. Such characteristics can make small and mid-size companies more sensitive to changing economic conditions. REIT stocks tend to have a significant amount of dividend income, which can reduce the impact of this volatility. However, the Fund is subject to additional risk because of the concentration in the real estate sector. This focus on a single sector may result in more risk than that for a more diversified, multisector portfolio.

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The Fund is subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund‘s target index may, at times, become focused in stocks of a limited number of companies, which could cause the Fund to underperform the overall stock market.

To illustrate the volatility of stock prices, the following table shows the best, worst, and average annual total returns for the U.S. stock market over various periods as measured by the S&P 500 Index, a widely used barometer of U.S. stock market activity. Total returns consist of dividend income plus change in market price. Note that the returns shown do not include the costs of buying and selling stocks or other expenses that a real-world investment portfolio would incur.

The table covers all of the rolling 1-, 5-, 10-, and 20-year periods from 1926 through 2016. You can see, for example, that although the average annual return on common stocks for all of the 5-year periods was 10.1%, average annual returns for individual 5-year periods ranged from –12.4% (from 1928 through 1932) to 28.6% (from 1995 through 1999). These average annual returns reflect past performance of common stocks; you should not regard them as an indication of future performance of either the stock market as a whole or the Fund in particular.

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The Fund is subject to interest rate risk, which is the chance that REIT stock prices overall will decline and that the cost of borrowing for REITs will increase because of rising interest rates. Interest rate risk is high for the Fund.

In general, during periods of high interest rates, REITs may lose some of their appeal for investors who may be able to obtain higher yields from other income-producing investments, such as long-term bonds. Higher interest rates also mean that financing for property purchases and improvements is more costly and difficult to obtain.

The Fund is subject to industry concentration risk, which is the chance that the stocks of REITs will decline because of adverse developments affecting the real estate industry and real property values. Because the Fund concentrates its assets in REIT stocks, industry concentration risk is high.

Because of its emphasis on REIT stocks, the Fund’s performance may at times be linked to the ups and downs of the real estate market. In general, real estate values can be affected by a variety of factors, including, but not limited to, supply and demand for properties, the economic health of the nation as well as different regions, and the strength of specific industries that rent properties. Ultimately, an individual REIT’s performance depends on the types and locations of the properties it owns and on how well the REIT manages its properties. For instance, rental income could decline because of extended vacancies, increased competition from nearby properties, tenants’ failure to pay rent, regulatory limitations on rents, fluctuations in rental income, variations in market rental rates, or incompetent management. Property values could decrease because of overbuilding in the area, environmental liabilities, uninsured damages caused by natural disasters, a general decline in the neighborhood, losses because of casualty or condemnation, increases in property taxes, or changes in zoning laws. Loss of IRS status as a qualified REIT may also affect an individual REIT’s performance. In addition, many real estate issuers, including REITs, utilize leverage (and some may be highly leveraged), which increases investment risk and could adversely affect the issuer’s operations and market value in periods of rising interest rates.

Security Selection

The Fund attempts to track the investment performance of a benchmark index that measures the performance of publicly traded equity REITs.

The Fund attempts to hold each stock contained in the MSCI US REIT Index either directly or indirectly through the underlying fund in roughly the same proportion as represented in the Index itself. For example, if 5% of the MSCI US REIT Index were made up of the stock of a specific REIT, the Fund would seek to invest approximately the same percentage of its assets in that stock.

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The MSCI US REIT Index is a free-float adjusted market-cap weighted index. It is made up of the stocks of publicly traded equity REITs that meet certain criteria. For example, to be included initially in the Index, a REIT must meet a minimum market capitalization threshold and have enough shares and trading volume to be considered liquid. In line with the Index, the Fund invests in equity REITs only.

The Fund is subject to asset concentration risk, which is the chance that, because the Fund’s target index (and therefore the Fund) tends to be heavily weighted in its ten largest holdings, the Fund’s performance may be hurt disproportionately by the poor performance of relatively few stocks.

As of January 31, 2017, 155 equity REITs were included in the Index. On a quarterly basis, the Index is rebalanced and its current stocks are tested for continued compliance with the guidelines of the Index. A REIT may be removed from the Index because of a decline in market capitalization, because it becomes illiquid, or because of other changes in its status.

Stocks in the MSCI US REIT Index represent a broadly diversified range of property types. The makeup of the Fund, as of January 31, 2017, was:

Other Investment Policies and Risks

The Fund reserves the right to substitute a different index for the index it currently tracks if the current index is discontinued, if the Fund‘s agreement with the sponsor of its target index is terminated, or for any other reason determined in good faith by the Fund’s board of trustees. In any such instance, the substitute index would represent the same market segment as the current index.

The Fund is subject to REIT ownership limitation risk, which is the chance that the Fund may be unable to purchase (or otherwise obtain economic exposure, including through investing in the underlying fund, to) the desired amounts of certain REITs included in its target index.

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The Fund has significant ownership positions in many REITs included in its target index. For tax and other reasons, a REIT imposes limits on how much of its securities investors may own. If an ownership limit is reached, Vanguard may seek to obtain an ownership waiver from the REIT to exceed the limit. If the Fund is unable to obtain a waiver or an existing waiver is terminated, then the Fund may seek to obtain economic exposure to the REIT through alternative means, such as through a total return swap, which may be more costly than owning REIT shares directly. If the Fund is unable to obtain either an ownership waiver or economic exposure to the REIT through alternative means, the Fund may experience increased tracking error. In addition, to maintain its qualification as a regulated investment company for tax purposes, the Fund may be unable to obtain additional economic exposure to certain REITs, which may increase tracking error. Additional measures could be taken in the future in response to REIT ownership limits, including changing the Fund’s investment strategy, imposing purchase fees on or prohibiting the issuance of Creation Units, or any other appropriate action. If additional measures are pursued, market price and NAV may differ significantly and liquidity may be reduced.

The Fund may invest a portion of its assets in the underlying fund. The underlying fund will also employ an indexing investment approach designed to track the performance of the MSCI US REIT Index. The underlying fund’s investments are subject to the same risks as if they were held directly by the Fund. Because the strategy of the underlying fund will be substantially similar to that of the Fund, the principal risks of the Fund’s investment in the underlying fund will not be materially different from the risks associated with the Fund’s other investments. However, the Fund’s investment in the underlying fund is subject to the ongoing existence of the underlying fund and the underlying fund’s ability to provide economic exposure to REITs included in the Fund’s target index.

If the Fund is unable to invest directly or through the underlying fund or to obtain exposure to REITs through alternative means, then the Fund may be unable to own the desired amount of certain REITs, which may increase tracking error.

The Fund may invest in foreign securities to the extent necessary to carry out its investment strategy of holding all, or substantially all, of the stocks that make up the index it tracks.

In addition to investing in common stocks of REITs, the Fund may make other kinds of investments to achieve its objective.

The Fund may invest in derivatives. In general, investments in derivatives may involve risks different from, and possibly greater than, those of investments directly in the underlying securities or assets.

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Generally speaking, a derivative is a financial contract whose value is based on the value of a financial asset (such as a stock, a bond, or a currency), a physical asset (such as gold, oil, or wheat), a market index (such as the S&P 500 Index), or a reference rate (such as LIBOR). The Fund may invest in derivatives only if the expected risks and rewards of the derivatives are consistent with the investment objective, policies, strategies, and risks of the Fund as disclosed in this prospectus. In particular, derivatives will be used only when they may help the advisor to accomplish one or more of the following:

• Invest in eligible asset classes with greater efficiency and lower cost than is possible through direct investment.

• Obtain economic exposure to a stock, a basket of stocks, or an index when deemed desirable or necessary.

• Add value when these instruments are attractively priced.

The market for many derivatives is, or suddenly can become, illiquid, which may result in significant, rapid, and unpredictable changes in the prices for derivatives. The Fund‘s use of a derivative subjects it to the risk of nonperformance by the counterparty, potentially resulting in delayed or partial payment or even nonpayment of amounts due under the derivative contract. The Fund attempts to mitigate this risk by requiring the posting of collateral by its counterparty.

The Fund‘s derivative investments may include total return swaps or other derivatives.

Cash Management

The Fund‘s daily cash balance may be invested in one or more Vanguard CMT Funds, which are very low-cost money market funds. When investing in a Vanguard CMT Fund, the Fund bears its proportionate share of the expenses of the CMT Fund in which it invests. Vanguard receives no additional revenue from Fund assets invested in a Vanguard CMT Fund.

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Methods Used to Meet Redemption Requests

Redemptions of the ETF shares are typically met through a combination of cash and securities held by the Fund; see “How Are Vanguard ETF Shares Different From Conventional Mutual Fund Shares?”. If cash is used to meet redemptions, the Fund typically obtains such cash through positive cash flows or the sale of Fund holdings consistent with the Fund’s investment objective and strategy. Please consult the Fund’s Statement of Additional Information for further information on redemptions of ETF Shares.

Under certain circumstances, the Fund may borrow money (subject to certain regulatory conditions and if available under board-approved procedures) through an interfund lending facility or through a bank line-of-credit, including a joint committed credit facility, in order to meet redemption requests.

Temporary Investment Measures

The Fund may temporarily depart from its normal investment policies and strategies when the advisor believes that doing so is in the Fund‘s best interest, so long as the departure is consistent with the Fund‘s investment objective. For instance, the Fund may invest beyond its normal limits in derivatives or exchange-traded funds that are consistent with the Fund‘s objective when those instruments are more favorably priced or provide needed liquidity, as might be the case when the Fund receives large cash flows that it cannot prudently invest immediately.

Special Risks of Exchange-Traded Shares

ETF Shares are not individually redeemable. They can be redeemed with the issuing Fund at NAV only by authorized broker-dealers and only in large blocks known as Creation Units, which would cost millions of dollars to assemble. Consequently, if you want to liquidate some or all of your ETF Shares, you must sell them on the secondary market at prevailing market prices.

The market price of ETF Shares may differ from NAV. Although it is expected that the market price of an ETF Share typically will approximate its NAV, there may be times when the market price and the NAV differ significantly. Thus, you may pay more (premium) or less (discount) than NAV when you buy ETF Shares on the secondary market, and you may receive more or less than NAV when you sell those shares. These discounts and premiums are likely to be greatest during times of market disruption or extreme market volatility.

Vanguard’s website at vanguard.com shows the previous day’s closing NAV and closing market price for the Fund’s ETF Shares. The website also discloses, in the Premium/Discount Analysis section of the ETF Shares’ Price & Performance page,

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how frequently the Fund’s ETF Shares traded at a premium or discount to NAV (based on closing NAVs and market prices) and the magnitudes of such premiums and discounts.

An active trading market may not exist. Although Vanguard ETF Shares are listed on a national securities exchange, it is possible that an active trading market may not be maintained. Although this could happen at any time, it is more likely to occur during times of severe market disruption. If you attempt to sell your ETF Shares when an active trading market is not functioning, you may have to sell at a significant discount to NAV. In extreme cases, you may not be able to sell your shares at all.

Trading may be halted. Trading of Vanguard ETF Shares on an exchange may be halted by the activation of individual or marketwide trading halts (which halt trading for a specific period of time when the price of a particular security or overall market prices decline by a specified percentage). Trading of ETF Shares may also be halted if (1) the shares are delisted from the listing exchange without first being listed on another exchange or (2) exchange officials determine that such action is appropriate in the interest of a fair and orderly market or for the protection of investors.

Conversion Privilege

Owners of conventional shares issued by the Fund may convert those shares to ETF Shares of equivalent value of the same fund. Please note that investors who own conventional shares through a 401(k) plan or other employer-sponsored retirement or benefit plan generally may not convert those shares to ETF Shares and should check with their plan sponsor or recordkeeper. ETF Shares, whether acquired through a conversion or purchased on the secondary market, cannot be converted to conventional shares by a shareholder. Also, ETF Shares of one fund cannot be exchanged for ETF Shares of another fund.

You must hold ETF Shares in a brokerage account. Thus, before converting conventional shares to ETF Shares, you must have an existing, or open a new, brokerage account. This account may be with Vanguard Brokerage Services^® (Vanguard Brokerage) or with any other brokerage firm. To initiate a conversion of conventional shares to ETF Shares, please contact your broker.

Vanguard Brokerage does not impose a fee on conversions from Vanguard conventional shares to Vanguard ETF Shares. However, other brokerage firms may charge a fee to process a conversion. Vanguard reserves the right, in the future, to impose a transaction fee on conversions or to limit or terminate the conversion privilege.

Converting conventional shares to ETF Shares is generally accomplished as follows. First, after your broker notifies Vanguard of your request to convert, Vanguard will transfer your conventional shares from your account to the broker’s omnibus account

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with Vanguard (an account maintained by the broker on behalf of all its customers who hold conventional Vanguard fund shares through the broker). After the transfer, Vanguard’s records will reflect your broker, not you, as the owner of the shares. Next, your broker will instruct Vanguard to convert the appropriate number or dollar amount of conventional shares in its omnibus account to ETF Shares of equivalent value, based on the respective NAVs of the two share classes.

Your Fund’s transfer agent will reflect ownership of all ETF Shares in the name of the Depository Trust Company (DTC). The DTC will keep track of which ETF Shares belong to your broker, and your broker, in turn, will keep track of which ETF Shares belong to you.

Because the DTC is unable to handle fractional shares, only whole shares can be converted. For example, if you owned 300.250 conventional shares, and this was equivalent in value to 90.750 ETF Shares, the DTC account would receive 90 ETF Shares. Conventional shares with a value equal to 0.750 ETF Shares (in this example, that would be 2.481 conventional shares) would remain in the broker’s omnibus account with Vanguard. Your broker then could either (1) credit your account with 0.750 ETF Shares or (2) redeem the 2.481 conventional shares for cash at NAV and deliver that cash to your account. If your broker chose to redeem your conventional shares, you would realize a gain or loss on the redemption that must be reported on your tax return (unless you hold the shares in an IRA or other tax-deferred account). Please consult your broker for information on how it will handle the conversion process, including whether it will impose a fee to process a conversion.

If you convert your conventional shares to ETF Shares through Vanguard Brokerage, all conventional shares for which you request conversion will be converted to ETF Shares of equivalent value. Because no fractional shares will have to be sold, the transaction will not be taxable.

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Here are some important points to keep in mind when converting conventional shares of a Vanguard fund to ETF Shares:

• The conversion process can take anywhere from several days to several weeks, depending on your broker. Vanguard generally will process conversion requests either on the day they are received or on the next business day. Vanguard imposes conversion blackout windows around the dates when a fund with ETF Shares declares dividends. This is necessary to prevent a shareholder from collecting a dividend from both the conventional share class currently held and also from the ETF share class to which the shares will be converted.

• Until the conversion process is complete, you will remain fully invested in a fund’s conventional shares, and your investment will increase or decrease in value in tandem with the NAV of those shares.

• The conversion transaction is nontaxable except, if applicable, to the very limited extent previously described.

A precautionary note to investment companies: Vanguard ETF Shares are issued by registered investment companies, and therefore the acquisition of such shares by other investment companies is subject to the restrictions of Section 12(d)(1) of the Investment Company Act of 1940. Vanguard has obtained an SEC exemptive order that allows investment companies to invest in the issuing funds beyond the limits of Section 12(d)(1), subject to certain terms and conditions, including the requirement to enter into a participation agreement with Vanguard. The exemptive order is not, however, available to the Fund. Accordingly, investment companies seeking to invest in the Fund must adhere to the limits set forth in Section 12(d)(1) of the Investment Company Act of 1940.

Frequent Trading and Market-Timing

Unlike frequent trading of a Vanguard fund’s conventional (i.e., not exchange-traded) classes of shares, frequent trading of ETF Shares does not disrupt portfolio management, increase the fund’s trading costs, lead to realization of capital gains by the fund, or otherwise harm fund shareholders. The vast majority of trading in ETF Shares occurs on the secondary market. Because these trades do not involve the issuing fund, they do not harm the fund or its shareholders. A few institutional investors are authorized to purchase and redeem ETF Shares directly with the issuing fund. Because these trades typically are effected in kind (i.e., for securities and not for cash), they do not cause any of the harmful effects to the issuing fund (as previously noted) that may result from frequent cash trades. For these reasons, the board of trustees of each fund that issues ETF Shares has determined that it is not necessary to adopt policies and procedures to detect and deter frequent trading and market-timing of ETF Shares.

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Portfolio Holdings

Please consult the Fund‘s Statement of Additional Information or our website for a description of the policies and procedures that govern disclosure of the Fund’s portfolio holdings.

Turnover Rate

Although the Fund generally seeks to invest for the long term, it may sell securities regardless of how long they have been held. Generally, an index fund sells securities in response to redemption requests from shareholders of conventional (not exchange-traded) shares or to changes in the composition of its target index. The Financial Highlights section of this prospectus shows historical turnover rates for the Fund. A turnover rate of 100%, for example, would mean that the Fund had sold and replaced securities valued at 100% of its net assets within a one-year period.

The Fund and Vanguard

The Fund is a member of The Vanguard Group, a family of more than 190 mutual funds holding assets of approximately $3.7 trillion. All of the funds that are members of The Vanguard Group (other than funds of funds) share in the expenses associated with administrative services and business operations, such as personnel, office space, and equipment.

Vanguard Marketing Corporation provides marketing services to the funds. Although shareholders do not pay sales commissions or 12b-1 distribution fees, each fund (other than a fund of funds) or each share class of a fund (in the case of a fund with multiple share classes) pays its allocated share of the Vanguard funds’ marketing costs.

To the extent that the Fund’s assets are invested in another Vanguard fund, including a wholly owned subsidiary, such assets will be excluded when allocating to the Fund its share of the costs of Vanguard’s operations.

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Investment Advisor

The Vanguard Group, Inc. (Vanguard), P.O. Box 2600, Valley Forge, PA 19482, which began operations in 1975, serves as advisor to the Fund through its Equity Index Group. As of January 31, 2017, Vanguard served as advisor for approximately $3.2 trillion in assets. Vanguard provides investment advisory services to the Fund on an at-cost basis, subject to the supervision and oversight of the trustees and officers of the Fund.

For the fiscal period ended January 31, 2017, the advisory expenses represented an effective annual rate of 0.01% of the Fund’s average net assets.

For a discussion of why the board of trustees approved the Fund’s investment advisory arrangement, see the most recent semiannual report to shareholders covering the fiscal period ended July 31.

The managers primarily responsible for the day-to-day management of the Fund are:

Walter Nejman, Portfolio Manager at Vanguard. He has been with Vanguard since 2005, has worked in investment management since 2008, and has co-managed the Fund since 2016. Education: B.A., Arcadia University; M.B.A., Villanova University.

Gerard C. O’Reilly, Principal of Vanguard. He has been with Vanguard since 1992, has managed investment portfolios since 1994, and has managed the Fund since its inception in 1996 (co-managed since 2016). Education: B.S., Villanova University.

The Statement of Additional Information provides information about each portfolio manager’s compensation, other accounts under management, and ownership of shares of the Fund.

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Dividends, Capital Gains, and Taxes

Fund Distributions

Each March, June, September, and December, the Fund pays out to shareholders virtually all of the distributions it receives from its REIT investments, less expenses. Distributions may include income, return of capital, and capital gains. The Fund may also realize capital gains on the sale of its REIT investments. Distributions of these gains, if any, are included in the December distribution. In addition, the Fund may occasionally make a supplemental distribution at some other time during the year.

Reinvestment of Distributions

In order to reinvest distributions, investors in the Fund’s ETF Shares must hold their shares at a broker that offers a reinvestment service. This can be the broker’s own service or a service made available by a third party, such as the broker’s outside clearing firm or the Depository Trust Company (DTC). If a reinvestment service is available, distributions can automatically be reinvested in additional whole and fractional ETF Shares of the Fund. If a reinvestment service is not available, investors will receive their distributions in cash. To determine whether a reinvestment service is available and whether there is a commission or other charge for using this service, consult your broker.

As with all exchange-traded funds, reinvestment of distributions in additional ETF

Shares will occur four business days or more after the ex-dividend date (the date

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when a distribution is deducted from the price of the Fund’s shares). The exact number of days depends on your broker. During that time, the amount of your distribution will not be invested in the Fund and therefore will not share in the Fund’s income, gains, and losses.

Basic Tax Points

Investors in taxable accounts should be aware of the following basic federal income tax points:

• Distributions (other than any return of capital) are taxable to you whether or not you reinvest these amounts in additional ETF Shares.

• Distributions declared in December—if paid to you by the end of January—are taxable as if received in December.

• Any dividend distribution or short-term capital gains distribution that you receive is taxable to you as ordinary income. If you are an individual and meet certain holding-period requirements with respect to your ETF Shares, you may be eligible for reduced tax rates on “qualified dividend income,” if any, distributed by the Fund. Dividend distributions attributable to the Fund’s REIT investments are generally not eligible for qualified dividend income treatment.

• Any distribution of net long-term capital gains is taxable to you as long-term capital gains, no matter how long you have owned ETF Shares.

• Capital gains distributions may vary considerably from year to year as a result of the Fund‘s normal investment activities and cash flows.

• A sale of ETF Shares is a taxable event. This means that you may have a capital gain to report as income, or a capital loss to report as a deduction, when you complete your tax return.

• Dividend distributions attributable to the Fund’s REIT investments are generally not eligible for the corporate dividends-received deduction.

• Your cost basis in the Fund will be decreased by the amount of any return of capital that you receive. This, in turn, will affect the amount of any capital gain or loss that you realize when selling your ETF Shares.

• Return-of-capital distributions generally are not taxable to you until your cost basis has been reduced to zero. If your cost basis is at zero, return-of-capital distributions will be treated as capital gains.

Individuals, trusts, and estates whose income exceeds certain threshold amounts are subject to a 3.8% Medicare contribution tax on “net investment income.” Net investment income takes into account distributions paid by the Fund and capital gains from any sale of ETF Shares.

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Dividend distributions and capital gains distributions that you receive, as well as your gains or losses from any sale of ETF Shares, may be subject to state and local income taxes.

This prospectus provides general tax information only. If you are investing through a tax-advantaged account, such as an IRA or an employer-sponsored retirement or savings plan, special tax rules apply. Please consult your tax advisor for detailed information about any tax consequences for you.

Share Price and Market Price

Share price, also known as net asset value (NAV), is calculated each business day as of the close of regular trading on the New York Stock Exchange (NYSE), generally 4 p.m., Eastern time. Each share class has its own NAV, which is computed by dividing the total assets, minus liabilities, allocated to the share class by the number of Fund shares outstanding for that class. On U.S. holidays or other days when the NYSE is closed, the NAV is not calculated, and the Fund does not sell or redeem shares. However, on those days the value of the Fund’s assets may be affected to the extent that the Fund holds securities that change in value on those days (such as foreign securities that trade on foreign markets that are open).

Remember: If you buy or sell ETF Shares on the secondary market, you will pay or receive the market price, which may be higher or lower than NAV. Your transaction will be priced at NAV only if you purchase or redeem your ETF Shares in Creation Unit blocks (an option available only to certain authorized broker-dealers) or if you convert your conventional fund shares to ETF Shares.

Stocks held by a Vanguard fund are valued at their market value when reliable market quotations are readily available from the principal exchange or market on which they are traded. Such securities are generally valued at their official closing price, the last reported sales price, or if there were no sales that day, the mean between the closing bid and asking prices. When a fund determines that market quotations either are not readily available or do not accurately reflect the value of a security, the security is priced at its fair value (the amount that the owner might reasonably expect to receive upon the current sale of the security).

The values of any foreign securities held by a fund are converted into U.S. dollars using an exchange rate obtained from an independent third party as of the close of regular trading on the NYSE. The values of any mutual fund shares, including institutional money market fund shares, held by a fund are based on the NAVs of the shares. The values of any ETF shares or closed-end fund shares held by a fund are based on the market value of the shares.

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A fund also will use fair-value pricing if the value of a security it holds has been materially affected by events occurring before the fund’s pricing time but after the close of the principal exchange or market on which the security is traded. This most commonly occurs with foreign securities, which may trade on foreign exchanges that close many hours before the fund’s pricing time. Intervening events might be company-specific (e.g., earnings report, merger announcement) or country-specific or regional/global (e.g., natural disaster, economic or political news, act of terrorism, interest rate change). Intervening events include price movements in U.S. markets that exceed a specified threshold or that are otherwise deemed to affect the value of foreign securities.

Fair-value pricing may be used for domestic securities—for example, if (1) trading in a security is halted and does not resume before the fund’s pricing time or a security does not trade in the course of a day and (2) the fund holds enough of the security that its price could affect the NAV.

Fair-value prices are determined by Vanguard according to procedures adopted by the board of trustees. When fair-value pricing is employed, the prices of securities used by a fund to calculate the NAV may differ from quoted or published prices for the same securities.

Vanguard’s website will show the previous day’s closing NAV and closing market price for the Fund’s ETF Shares.

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Financial Highlights

The following financial highlights table is intended to help you understand the ETF Shares‘ financial performance for the periods shown, and certain information reflects financial results for a single ETF Share. The total returns in the table represent the rate that an investor would have earned or lost each period on an investment in the ETF Shares (assuming reinvestment of all distributions). This information has been obtained from the financial statements audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, whose report—along with the Fund’s financial statements—is included in the Fund’s most recent annual report to shareholders. You may obtain a free copy of the latest annual or semiannual report by visiting vanguard.com or by contacting Vanguard by telephone or mail.

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1 Excludes the value of portfolio securities received or delivered as a result of in-kind purchases or redemptions of the Fund’s capital shares, including ETF Creation Units.

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THIS FUND IS NOT SPONSORED, ENDORSED, SOLD OR PROMOTED BY MSCI INC. (“MSCI”), ANY OF ITS AFFILIATES, ANY OF ITS DIRECT OR INDIRECT INFORMATION PROVIDERS OR ANY OTHER THIRD PARTY INVOLVED IN, OR RELATED TO, COMPILING, COMPUTING OR CREATING ANY MSCI INDEX (COLLECTIVELY, THE “MSCI PARTIES”). THE MSCI INDEXES ARE THE EXCLUSIVE PROPERTY OF MSCI. MSCI AND THE MSCI INDEX NAMES ARE SERVICE MARK(S) OF MSCI OR ITS AFFILIATES AND HAVE BEEN LICENSED FOR USE FOR CERTAIN PURPOSES BY VANGUARD. NONE OF THE MSCI PARTIES MAKES ANY REPRESENTATION OR WARRANTY, EXPRESS OR IMPLIED, TO THE OWNERS OF THIS FUND OR ANY MEMBER OF THE PUBLIC REGARDING THE ADVISABILITY OF INVESTING IN FUNDS GENERALLY OR IN THIS FUND PARTICULARLY OR THE ABILITY OF ANY MSCI INDEX TO TRACK CORRESPONDING STOCK MARKET PERFORMANCE. MSCI OR ITS AFFILIATES ARE THE LICENSORS OF CERTAIN TRADEMARKS, SERVICE MARKS AND TRADE NAMES AND OF THE MSCI INDEXES WHICH ARE DETERMINED, COMPOSED AND CALCULATED BY MSCI WITHOUT REGARD TO THIS FUND OR THE ISSUER OR OWNER OF THIS FUND. NONE OF THE MSCI PARTIES HAS ANY OBLIGATION TO TAKE THE NEEDS OF THE ISSUERS OR OWNERS OF THIS FUND INTO CONSIDERATION IN DETERMINING, COMPOSING OR CALCULATING THE MSCI INDEXES. NONE OF THE MSCI PARTIES IS RESPONSIBLE FOR OR HAS PARTICIPATED IN THE DETERMINATION OF THE TIMING OF, PRICES AT, OR QUANTITIES OF THIS FUND TO BE ISSUED OR IN THE DETERMINATION OR CALCULATION OF THE CONSIDERATION INTO WHICH THIS FUND IS REDEEMABLE. NONE OF THE MSCI PARTIES HAS ANY OBLIGATION OR LIABILITY TO THE OWNERS OF THIS FUND IN CONNECTION WITH THE ADMINISTRATION, MARKETING OR OFFERING OF THIS FUND.

ALTHOUGH MSCI SHALL OBTAIN INFORMATION FOR INCLUSION IN OR FOR USE IN THE CALCULATION OF THE MSCI INDEXES FROM SOURCES WHICH MSCI CONSIDERS RELIABLE, NONE OF THE MSCI PARTIES WARRANTS OR GUARANTEES THE ORIGINALITY, ACCURACY AND/OR THE COMPLETENESS OF ANY MSCI INDEX OR ANY DATA INCLUDED THEREIN. NONE OF THE MSCI PARTIES MAKES ANY WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY LICENSEE, LICENSEE’S CUSTOMERS OR COUNTERPARTIES, ISSUERS OF THE FUNDS, OWNERS OF THE FUNDS, OR ANY OTHER PERSON OR ENTITY, FROM THE USE OF ANY MSCI INDEX OR ANY DATA INCLUDED THEREIN IN CONNECTION WITH THE RIGHTS LICENSED HEREUNDER OR FOR ANY OTHER USE. NONE OF THE MSCI PARTIES SHALL HAVE ANY LIABILITY FOR ANY ERRORS, OMISSIONS OR INTERRUPTIONS OF OR IN CONNECTION WITH ANY MSCI INDEX OR ANY DATA INCLUDED THEREIN. FURTHER, NONE OF THE MSCI PARTIES MAKES ANY EXPRESS OR IMPLIED WARRANTIES OF ANY KIND, AND THE MSCI PARTIES HEREBY EXPRESSLY DISCLAIM ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, WITH RESPECT TO ANY MSCI INDEX AND ANY DATA INCLUDED THEREIN. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT SHALL ANY OF THE MSCI PARTIES HAVE ANY LIABILITY FOR ANY DIRECT, INDIRECT, SPECIAL, PUNITIVE, CONSEQUENTIAL OR ANY OTHER DAMAGES (INCLUDING WITHOUT LIMITATION LOST PROFITS) EVEN IF NOTIFIED OF THE POSSIBILITY OF SUCH DAMAGES.

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Glossary of Investment Terms

Active Management. An investment approach that seeks to exceed the average returns of a particular financial market or market segment. In selecting securities to buy and sell, active managers may rely on, among other things, research, market forecasts, quantitative models, and their own judgment and experience.

Authorized Participant. Institutional investors that are permitted to purchase Creation Units directly from, and redeem Creation Units directly with, the issuing fund. To be an Authorized Participant, an entity must be a participant in the Depository Trust Company and must enter into an agreement with the fund’s Distributor.

Bid-Ask Spread. The difference between the price a dealer is willing to pay for a security (the bid price) and the somewhat higher price at which the dealer is willing to sell the same security (the ask price).

Capital Gains Distribution. Payment to mutual fund shareholders of gains realized on securities that a fund has sold at a profit, minus any realized losses.

Common Stock. A security representing ownership rights in a corporation.

Cost Basis. The adjusted cost of an investment, used to determine a capital gain or loss for tax purposes.

Creation Unit. A large block of a specified number of ETF Shares. Certain broker-dealers known as “Authorized Participants” may purchase and redeem ETF Shares from the issuing fund in Creation Unit size blocks.

Distributions. Payments to mutual fund shareholders of dividend income, capital gains, and return of capital generated by the fund’s investment activities and distribution policies, after expenses.

Dividend Distribution. Payment to mutual fund shareholders of income from interest or dividends generated by a fund’s investments.

Ex-Dividend Date. The date when a distribution of dividends and/or capital gains is deducted from the share price of a mutual fund or stock. On the ex-dividend date, the share price drops by the amount of the distribution per share (plus or minus any market activity).

Expense Ratio. A fund’s total annual operating expenses expressed as a percentage of the fund’s average net assets. The expense ratio includes management and administrative expenses, but it does not include the transaction costs of buying and selling portfolio securities.

Inception Date. The date on which the assets of a fund (or one of its share classes) are first invested in accordance with the fund’s investment objective. For funds with a subscription period, the inception date is the day after that period ends. Investment performance is generally measured from the inception date.

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Indexing. A low-cost investment strategy in which a mutual fund attempts to track—rather than outperform—a specified market benchmark, or “index.”

Joint Committed Credit Facility. The Fund and certain other funds managed by Vanguard participate in a committed credit facility provided by a syndicate of lenders pursuant to a credit agreement that may be renewed annually; each fund is individually liable for its borrowings, if any, under the credit facility. The amount and terms of the committed credit facility are subject to approval by the fund’s board of trustees and renegotiation with the lender syndicate on an annual basis.

Liquidity. The degree of a security’s marketability (i.e., how quickly the security can be sold at a fair price and converted to cash).

Median Market Capitalization. An indicator of the size of companies in which a fund invests; the midpoint of market capitalization (market price x shares outstanding) of a fund’s stocks, weighted by the proportion of the fund’s assets invested in each stock. Stocks representing half of the fund’s assets have market capitalizations above the median, and the rest are below it.

Mutual Fund. An investment company that pools the money of many people and invests it in a variety of securities in an effort to achieve a specific objective over time.

New York Stock Exchange (NYSE). A stock exchange based in New York City that is open for regular trading on business days, Monday through Friday, from 9:30 a.m. to 4 p.m., Eastern time. Net asset values (NAVs) are calculated each business day as of the close of regular trading on the NYSE. In the rare event the NYSE experiences unanticipated trade disruptions and is unavailable at the close of the trading day, NAVs will be calculated as of the close of regular trading on the Nasdaq (or another alternate exchange if the Nasdaq is unavailable), generally 4 p.m., Eastern time.

Return of Capital. A return of all or part of your original investment in a fund. In general, return of capital reduces your cost basis in a fund’s shares and is not taxable to you until your cost basis has been reduced to zero.

Securities. Stocks, bonds, money market instruments, and other investments.

Total Return. A percentage change, over a specified time period, in a mutual fund’s net asset value, assuming the reinvestment of all distributions of dividends and capital gains.

Tracking Error. A measure of the difference between the performance of a fund or portfolio and that of its benchmark index.

Volatility. The fluctuations in value of a mutual fund or other security. The greater a fund’s volatility, the wider the fluctuations in its returns.

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Wholly Owned Subsidiary. A company of which 95% or more of the outstanding voting securities are owned by another company, as defined by the Investment Company Act of 1940.

Yield. Income (interest or dividends) earned by an investment, expressed as a percentage of the investment’s price.

Connect with Vanguard^® > vanguard.com

For More Information

If you would like more information about Vanguard REIT ETF, the following documents are available free upon request:

Annual/Semiannual Reports to Shareholders

Additional information about the Fund’s investments is available in the Fund’s annual and semiannual reports to shareholders. In the annual report, you will find a discussion of the market conditions and investment strategies that significantly affected the Fund’s performance during its last fiscal year.

Statement of Additional Information (SAI)

The SAI provides more detailed information about the Fund’s ETF Shares and is incorporated by reference into (and thus legally a part of) this prospectus.

To receive a free copy of the latest annual or semiannual report or the SAI, or to request additional information about Vanguard ETF Shares, please visit vanguard.com or contact us as follows:

Information Provided by the Securities and Exchange Commission (SEC)

You can review and copy information about the Fund (including the SAI) at the SEC’s Public Reference Room in Washington, DC. To find out more about this public service, call the SEC at 202-551-8090. Reports and other information about the Fund are also available in the EDGAR database on the SEC’s website at www.sec.gov, or you can receive copies of this information, for a fee, by electronic request at the following email address: [email protected], or by writing the Public Reference Section, Securities and Exchange Commission, Washington, DC 20549-1520.

Fund’s Investment Company Act file number: 811-03916

The Vanguard Group
Institutional Investor Information
P.O. Box 2900
Valley Forge, PA 19482-2900
Telephone: 866-499-8473

• 2017 The Vanguard Group, Inc. All rights reserved.

• Patent Nos. 6,879,964; 7,337,138; 7,720,749; 7,925,573; 8,090,646;

and 8,417,623.

Vanguard Marketing Corporation, Distributor.

P 986 092017

Fund Summary

Investment Objective

The Fund seeks to provide a high level of income and moderate long-term capital appreciation by tracking the performance of a benchmark index that measures the performance of publicly traded equity REITs.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy and hold Institutional Shares of the Fund.

Example

The following example is intended to help you compare the cost of investing in the Fund’s Institutional Shares with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund’s shares. This example assumes that the shares provide a return of 5% each year and that total annual fund operating expenses remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

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Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 7% of the average value of its portfolio.

Principal Investment Strategies

The Fund employs an indexing investment approach designed to track the performance of the MSCI US REIT Index. The Index is composed of stocks of publicly traded equity real estate investment trusts (known as REITs). The Fund attempts to replicate the Index by investing all, or substantially all, of its assets—either directly or indirectly through a wholly owned subsidiary (the underlying fund), which is itself a registered investment company—in the stocks that make up the Index, holding each stock in approximately the same proportion as its weighting in the Index. The Fund may invest a portion of its assets in the underlying fund.

Principal Risks

An investment in the Fund could lose money over short or even long periods. You should expect the Fund’s share price and total return to fluctuate within a wide range. The Fund is subject to the following risks, which could affect the Fund’s performance:

• Industry concentration risk, which is the chance that the stocks of REITs will decline because of adverse developments affecting the real estate industry and real property values. Because the Fund concentrates its assets in REIT stocks, industry concentration risk is high.

• Stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund’s target index may, at times, become focused in stocks of a limited number of companies, which could cause the Fund to underperform the overall stock market.

• Interest rate risk, which is the chance that REIT stock prices overall will decline and that the cost of borrowing for REITs will increase because of rising interest rates. Interest rate risk is high for the Fund.

• Investment style risk, which is the chance that the returns from REIT stocks—which typically are small- or mid-capitalization stocks—will trail returns from the overall stock market. Historically, REIT stocks have performed quite differently from the overall market.

• Asset concentration risk, which is the chance that, because the Fund’s target index (and therefore the Fund) tends to be heavily weighted in its ten largest holdings, the

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Fund’s performance may be hurt disproportionately by the poor performance of relatively few stocks.

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund‘s Institutional Shares has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Institutional Shares compare with those of the Fund‘s target index and a comparative index, which have investment characteristics similar to those of the Fund. The REIT Spliced Index reflects performance of the MSCI US REIT Index adjusted to include a 2% cash position (Lipper Money Market Average) through April 30, 2009, and the MSCI US REIT Index thereafter. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard REIT Index Fund Institutional Shares¹

1 The year-to-date return as of the most recent calendar quarter, which ended on June 30, 2017, was 2.60%.

During the periods shown in the bar chart, the highest return for a calendar quarter was 34.56% (quarter ended September 30, 2009), and the lowest return for a quarter was –38.14% (quarter ended December 31, 2008).

3

Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder.

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Investment Advisor

The Vanguard Group, Inc. (Vanguard)

Portfolio Managers

Walter Nejman, Portfolio Manager at Vanguard. He has co-managed the Fund since 2016.

Gerard C. O’Reilly, Principal of Vanguard. He has managed the Fund since its inception in 1996 (co-managed since 2016).

Purchase and Sale of Fund Shares

You may purchase or redeem shares online through our website (vanguard.com), by mail (The Vanguard Group, P.O. Box 1110, Valley Forge, PA 19482-1110), or by telephone (800-662-2739). The minimum investment amount required to open and maintain a Fund account for Institutional Shares is $5 million. The minimum investment amount required to add to an existing Fund account is generally $1. If you are investing through an employer-sponsored retirement or savings plan, your plan administrator or your benefits office can provide you with detailed information on how to participate in your plan.

Tax Information

The Fund’s distributions may be taxable as ordinary income or capital gain or may constitute non–taxable return of capital. If you are investing through a tax-advantaged account, such as an IRA or an employer-sponsored retirement or savings plan, special tax rules apply.

Payments to Financial Intermediaries

The Fund and its investment advisor do not pay financial intermediaries for sales of Fund shares.

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Investing in Index Funds

What Is Indexing?

Indexing is an investment strategy for tracking the performance of a specified market benchmark, or “index.” An index is a group of securities whose overall performance is used as a standard to measure the investment performance of a particular market. There are many types of indexes. Some represent entire markets—such as the U.S. stock market or the U.S. bond market. Other indexes cover market segments—such as small-capitalization stocks or short-term bonds. The index sponsor determines the securities to include in the index, the weighting of each security in the index, and the appropriate time to make changes to the composition of the index. One cannot invest directly in an index.

An index fund holds all, or a representative sample, of the securities that make up its target index. Index funds attempt to mirror the performance of the target index, for better or worse. However, an index fund generally does not perform exactly like its target index. For example, index funds have operating expenses and transaction costs. Market indexes do not, and therefore they will usually have a slight performance advantage over funds that track them.

Index funds typically have the following characteristics:

• Variety of investments. Most Vanguard index funds generally invest in the securities of a variety of companies and industries.

• Relative performance consistency. Because they seek to track market benchmarks, index funds usually do not perform dramatically better or worse than their benchmarks.

• Low cost. Index funds are inexpensive to run compared with actively managed funds.

They have low or no research costs and typically keep trading activity—and thus brokerage commissions and other transaction costs—to a minimum compared with actively managed funds.

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More on the Fund

This prospectus describes the principal risks you would face as a Fund shareholder. It is important to keep in mind one of the main axioms of investing: generally, the higher the risk of losing money, the higher the potential reward. The reverse, also, is generally true: the lower the risk, the lower the potential reward. As you consider an investment in any mutual fund, you should take into account your personal tolerance for fluctuations in the securities markets. Look for this symbol throughout the prospectus. It is used to mark detailed information about the more significant risks that you would confront as a Fund shareholder. To highlight terms and concepts important to mutual fund investors, we have provided Plain Talk^® explanations along the way. Reading the prospectus will help you decide whether the Fund is the right investment for you. We suggest that you keep this prospectus for future reference.

Share Class Overview

This prospectus offers the Fund‘s Institutional Shares, which are generally for investors who invest a minimum of $5 million. A separate prospectus offers the Fund‘s Investor Shares and Admiral^™ Shares, which generally have investment minimums of $3,000 and $10,000, respectively. In addition, the Fund issues ETF Shares (an exchange-traded class of shares), which are also offered through a separate prospectus.

All share classes offered by the Fund have the same investment objective, strategies, and policies. However, different share classes have different expenses; as a result, their investment performances will differ.

A Similar But Different Fund

The Fund offered by this prospectus should not be confused with Vanguard REIT II Index Fund, a separate Vanguard fund that also seeks to track the performance of the MSCI US REIT Index and is anticipated to be the underlying fund. Both funds seek to replicate the stocks that make up the target index. This index replication strategy, combined with differences in the funds’ respective cash flows and expenses, is expected to produce slightly different investment performance by the funds. To obtain a prospectus for Vanguard REIT II Index Fund, institutional investors may call Vanguard’s Institutional Division at 888-809-8102 or may call their relationship managers directly.

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The following sections explain the principal investment strategies and policies that the Fund uses in pursuit of its objective. The Fund‘s board of trustees, which oversees the Fund’s management, may change investment strategies or policies in the interest of shareholders without a shareholder vote, unless those strategies or policies are designated as fundamental. Under normal circumstances, the Fund will invest at least 80% of its assets in the stocks that make up its target index. This policy may be changed only upon 60 days‘ notice to shareholders.

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Market Exposure

The Fund invests in stocks of publicly traded equity real estate investment trusts.

The Fund is subject to investment style risk, which is the chance that returns from REIT stocks—which typically are small- or mid-capitalization stocks—will trail returns from the overall stock market. Historically, REIT stocks have performed quite differently from the overall market.

Stocks of publicly traded companies and funds that invest in stocks are often classified according to market value, or market capitalization. These classifications typically include small-cap, mid-cap, and large-cap. It is important to understand that market capitalization ranges change over time. Also, interpretations of size vary, and there are no “official” definitions of small-, mid-, and large-cap, even among Vanguard fund advisors. REITs in the MSCI US REIT Index tend to be small- and mid-cap stocks. The asset-weighted median market capitalization of the Fund’s stock holdings as of January 31, 2017, was $10 billion.

Small- and mid-cap stocks tend to have greater volatility than large-cap stocks because, among other things, smaller companies often have fewer customers, financial resources, and products than larger firms. Such characteristics can make small and mid-size companies more sensitive to changing economic conditions. REIT stocks tend to have a significant amount of dividend income, which can reduce the impact of this volatility. However, the Fund is subject to additional risk because of the concentration in the real estate sector. This focus on a single sector may result in more risk than that for a more diversified, multisector portfolio.

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The Fund is subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund‘s target index may, at times, become focused in stocks of a limited number of companies, which could cause the Fund to underperform the overall stock market.

To illustrate the volatility of stock prices, the following table shows the best, worst, and average annual total returns for the U.S. stock market over various periods as measured by the S&P 500 Index, a widely used barometer of U.S. stock market activity. Total returns consist of dividend income plus change in market price. Note that the returns shown do not include the costs of buying and selling stocks or other expenses that a real-world investment portfolio would incur.

The table covers all of the rolling 1-, 5-, 10-, and 20-year periods from 1926 through 2016. You can see, for example, that although the average annual return on common stocks for all of the 5-year periods was 10.1%, average annual returns for individual 5-year periods ranged from –12.4% (from 1928 through 1932) to 28.6% (from 1995 through 1999). These average annual returns reflect past performance of common stocks; you should not regard them as an indication of future performance of either the stock market as a whole or the Fund in particular.

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The Fund is subject to interest rate risk, which is the chance that REIT stock prices overall will decline and that the cost of borrowing for REITs will increase because of rising interest rates. Interest rate risk is high for the Fund.

In general, during periods of high interest rates, REITs may lose some of their appeal for investors who may be able to obtain higher yields from other income-producing investments, such as long-term bonds. Higher interest rates also mean that financing for property purchases and improvements is more costly and difficult to obtain.

The Fund is subject to industry concentration risk, which is the chance that the stocks of REITs will decline because of adverse developments affecting the real estate industry and real property values. Because the Fund concentrates its assets in REIT stocks, industry concentration risk is high.

Because of its emphasis on REIT stocks, the Fund’s performance may at times be linked to the ups and downs of the real estate market. In general, real estate values can be affected by a variety of factors, including, but not limited to, supply and demand for properties, the economic health of the nation as well as different regions, and the strength of specific industries that rent properties. Ultimately, an individual REIT’s performance depends on the types and locations of the properties it owns and on how well the REIT manages its properties. For instance, rental income could decline because of extended vacancies, increased competition from nearby properties, tenants’ failure to pay rent, regulatory limitations on rents, fluctuations in rental income, variations in market rental rates, or incompetent management. Property values could decrease because of overbuilding in the area, environmental liabilities, uninsured damages caused by natural disasters, a general decline in the neighborhood, losses because of casualty or condemnation, increases in property taxes, or changes in zoning laws. Loss of IRS status as a qualified REIT may also affect an individual REIT’s performance. In addition, many real estate issuers, including REITs, utilize leverage (and some may be highly leveraged), which increases investment risk and could adversely affect the issuer’s operations and market value in periods of rising interest rates.

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Security Selection

The Fund attempts to track the investment performance of a benchmark index that measures the performance of publicly traded equity REITs.

The Fund attempts to hold each stock contained in the MSCI US REIT Index either directly or indirectly through the underlying fund in roughly the same proportion as represented in the Index itself. For example, if 5% of the MSCI US REIT Index were made up of the stock of a specific REIT, the Fund would seek to invest approximately the same percentage of its assets in that stock.

The MSCI US REIT Index is a free-float adjusted market-cap weighted index. It is made up of the stocks of publicly traded equity REITs that meet certain criteria. For example, to be included initially in the Index, a REIT must meet a minimum market capitalization threshold and have enough shares and trading volume to be considered liquid. In line with the Index, the Fund invests in equity REITs only.

The Fund is subject to asset concentration risk, which is the chance that, because the Fund’s target index (and therefore the Fund) tends to be heavily weighted in its ten largest holdings, the Fund’s performance may be hurt disproportionately by the poor performance of relatively few stocks.

As of January 31, 2017, 155 equity REITs were included in the Index. On a quarterly basis, the Index is rebalanced and its current stocks are tested for continued compliance with the guidelines of the Index. A REIT may be removed from the Index because of a decline in market capitalization, because it becomes illiquid, or because of other changes in its status.

Stocks in the MSCI US REIT Index represent a broadly diversified range of property types. The makeup of the Fund, as of January 31, 2017, was:

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Other Investment Policies and Risks

The Fund reserves the right to substitute a different index for the index it currently tracks if the current index is discontinued, if the Fund‘s agreement with the sponsor of its target index is terminated, or for any other reason determined in good faith by the Fund’s board of trustees. In any such instance, the substitute index would represent the same market segment as the current index.

The Fund is subject to REIT ownership limitation risk, which is the chance that the Fund may be unable to purchase (or otherwise obtain economic exposure, including through investing in the underlying fund, to) the desired amounts of certain REITs included in its target index.

The Fund has significant ownership positions in many REITs included in its target index. For tax and other reasons, a REIT imposes limits on how much of its securities investors may own. If an ownership limit is reached, Vanguard may seek to obtain an ownership waiver from the REIT to exceed the limit. If the Fund is unable to obtain a waiver or an existing waiver is terminated, then the Fund may seek to obtain economic exposure to the REIT through alternative means, such as through a total return swap, which may be more costly than owning REIT shares directly. If the Fund is unable to obtain either an ownership waiver or economic exposure to the REIT through alternative means, the Fund may experience increased tracking error. In addition, to maintain its qualification as a regulated investment company for tax purposes, the Fund may be unable to obtain additional economic exposure to certain REITs, which may increase tracking error. Additional measures could be taken in the future in response to REIT ownership limits, including changing the Fund’s investment strategy, limiting additional purchases into the Fund, or any other appropriate action.

The Fund may invest a portion of its assets in the underlying fund. The underlying fund will also employ an indexing investment approach designed to track the performance of the MSCI US REIT Index. The underlying fund’s investments are subject to the same risks as if they were held directly by the Fund. Because the strategy of the underlying fund will be substantially similar to that of the Fund, the principal risks of the Fund’s investment in the underlying fund will not be materially different from the risks associated with the Fund’s other investments. However, the Fund’s investment in the underlying fund is subject to the ongoing existence of the underlying fund and the underlying fund’s ability to provide economic exposure to REITs included in the Fund’s target index.

If the Fund is unable to invest directly or through the underlying fund or to obtain exposure to REITs through alternative means, then the Fund may be unable to own the desired amount of certain REITs, which may increase tracking error.

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The Fund may invest in foreign securities to the extent necessary to carry out its investment strategy of holding all, or substantially all, of the stocks that make up the index it tracks.

In addition to investing in common stocks of REITs, the Fund may make other kinds of investments to achieve its objective.

The Fund may invest in derivatives. In general, investments in derivatives may involve risks different from, and possibly greater than, those of investments directly in the underlying securities or assets.

Generally speaking, a derivative is a financial contract whose value is based on the value of a financial asset (such as a stock, a bond, or a currency), a physical asset (such as gold, oil, or wheat), a market index (such as the S&P 500 Index), or a reference rate (such as LIBOR). The Fund may invest in derivatives only if the expected risks and rewards of the derivatives are consistent with the investment objective, policies, strategies, and risks of the Fund as disclosed in this prospectus. In particular, derivatives will be used only when they may help the advisor to accomplish one or more of the following:

• Invest in eligible asset classes with greater efficiency and lower cost than is possible through direct investment.

• Obtain economic exposure to a stock, a basket of stocks, or an index when deemed desirable or necessary.

• Add value when these instruments are attractively priced.

The market for many derivatives is, or suddenly can become, illiquid, which may result in significant, rapid, and unpredictable changes in the prices for derivatives. The Fund‘s use of a derivative subjects it to the risk of nonperformance by the counterparty, potentially resulting in delayed or partial payment or even nonpayment of amounts due under the derivative contract. The Fund attempts to mitigate this risk by requiring the posting of collateral by its counterparty.

The Fund‘s derivative investments may include total return swaps or other derivatives.

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Cash Management

The Fund‘s daily cash balance may be invested in one or more Vanguard CMT Funds, which are very low-cost money market funds. When investing in a Vanguard CMT Fund, the Fund bears its proportionate share of the expenses of the CMT Fund in which it invests. Vanguard receives no additional revenue from Fund assets invested in a Vanguard CMT Fund.

Methods Used to Meet Redemption Requests

Under normal circumstances, the Fund typically expects to meet redemptions with other positive cash flows. When this is not an option, the Fund seeks to maintain its risk exposure by selling a cross section of the Fund’s holdings, including by making requests for redemptions from the underlying fund, to meet redemptions, while also factoring in transaction costs. Additionally, the Fund may work with larger clients to implement their redemptions in a manner that is least disruptive to the portfolio; see “Potentially disruptive redemptions.”

Under certain circumstances, including under stressed market conditions, there are additional tools that the Fund may use in order to meet redemptions, including advancing the settlement of market trades with counterparties to match investor redemption payments or delaying settlement of an investor’s transaction to match trade settlement within regulatory requirements. The Fund may also suspend payment of redemption proceeds for up to seven days; see “Emergency circumstances.” Additionally under these unusual circumstances, the Fund may borrow money (subject to certain regulatory conditions and if available under board-approved procedures) through an interfund lending facility or through a bank line-of-credit, including a joint committed credit facility, in order to meet redemption requests.

Temporary Investment Measures

The Fund may temporarily depart from its normal investment policies and strategies when the advisor believes that doing so is in the Fund‘s best interest, so long as the departure is consistent with the Fund‘s investment objective. For instance, the Fund may invest beyond its normal limits in derivatives or exchange-traded funds that are consistent with the Fund‘s objective when those instruments are more favorably priced or provide needed liquidity, as might be the case when the Fund receives large cash flows that it cannot prudently invest immediately.

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Frequent Trading or Market-Timing

Background. Some investors try to profit from strategies involving frequent trading of mutual fund shares, such as market-timing. For funds holding foreign securities, investors may try to take advantage of an anticipated difference between the price of the fund’s shares and price movements in overseas markets, a practice also known as time-zone arbitrage. Investors also may try to engage in frequent trading of funds holding investments such as small-cap stocks and high-yield bonds. As money is shifted into and out of a fund by a shareholder engaging in frequent trading, the fund incurs costs for buying and selling securities, resulting in increased brokerage and administrative costs. These costs are borne by all fund shareholders, including the long-term investors who do not generate the costs. In addition, frequent trading may interfere with an advisor’s ability to efficiently manage the fund.

Policies to address frequent trading. The Vanguard funds (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund) do not knowingly accommodate frequent trading. The board of trustees of each Vanguard fund (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund) has adopted policies and procedures reasonably designed to detect and discourage frequent trading and, in some cases, to compensate the fund for the costs associated with it. These policies and procedures do not apply to Vanguard ETF^® Shares because frequent trading in ETF Shares generally does not disrupt portfolio management or otherwise harm fund shareholders. Although there is no assurance that Vanguard will be able to detect or prevent frequent trading or market-timing in all circumstances, the following policies have been adopted to address these issues:

• Each Vanguard fund reserves the right to reject any purchase request—including exchanges from other Vanguard funds—without notice and regardless of size. For example, a purchase request could be rejected because the investor has a history of frequent trading or if Vanguard determines that such purchase may negatively affect a fund’s operation or performance.

• Each Vanguard fund (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund) generally prohibits, except as otherwise noted in the Investing With Vanguard section, an investor’s purchases or exchanges into a fund account for 30 calendar days after the investor has redeemed or exchanged out of that fund account.

• Certain Vanguard funds charge shareholders purchase and/or redemption fees on transactions.

See the Investing With Vanguard section of this prospectus for further details on Vanguard’s transaction policies.

Each Vanguard fund (other than retail and government money market funds), in determining its net asset value, will use fair-value pricing when appropriate, as

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described in the Share Price section. Fair-value pricing may reduce or eliminate the profitability of certain frequent-trading strategies.

Do not invest with Vanguard if you are a market-timer.

Turnover Rate

Although the Fund generally seeks to invest for the long term, it may sell securities regardless of how long they have been held. Generally, an index fund sells securities in response to redemption requests from shareholders of conventional (not exchange-traded) shares or to changes in the composition of its target index. The Financial Highlights section of this prospectus shows historical turnover rates for the Fund. A turnover rate of 100%, for example, would mean that the Fund had sold and replaced securities valued at 100% of its net assets within a one-year period.

The Fund and Vanguard

The Fund is a member of The Vanguard Group, a family of more than 190 mutual funds holding assets of approximately $3.7 trillion. All of the funds that are members of The Vanguard Group (other than funds of funds) share in the expenses associated with administrative services and business operations, such as personnel, office space, and equipment.

Vanguard Marketing Corporation provides marketing services to the funds. Although shareholders do not pay sales commissions or 12b-1 distribution fees, each fund (other than a fund of funds) or each share class of a fund (in the case of a fund with multiple share classes) pays its allocated share of the Vanguard funds’ marketing costs.

To the extent that the Fund’s assets are invested in another Vanguard fund, including a wholly owned subsidiary, such assets will be excluded when allocating to the Fund its share of the costs of Vanguard’s operations.

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Investment Advisor

The Vanguard Group, Inc. (Vanguard), P.O. Box 2600, Valley Forge, PA 19482, which began operations in 1975, serves as advisor to the Fund through its Equity Index Group. As of January 31, 2017, Vanguard served as advisor for approximately $3.2 trillion in assets. Vanguard provides investment advisory services to the Fund on an at-cost basis, subject to the supervision and oversight of the trustees and officers of the Fund.

For the fiscal year ended January 31, 2017, the advisory expenses represented an effective annual rate of 0.01% of the Fund’s average net assets.

For a discussion of why the board of trustees approved the Fund’s investment advisory arrangement, see the most recent semiannual report to shareholders covering the fiscal period ended July 31.

The managers primarily responsible for the day-to-day management of the Fund are:

Walter Nejman, Portfolio Manager at Vanguard. He has been with Vanguard since 2005, has worked in investment management since 2008, and has co-managed the Fund since 2016. Education: B.A., Arcadia University; M.B.A., Villanova University.

Gerard C. O’Reilly, Principal of Vanguard. He has been with Vanguard since 1992, has managed investment portfolios since 1994, and has managed the Fund since its inception in 1996 (co-managed since 2016). Education: B.S., Villanova University.

The Statement of Additional Information provides information about each portfolio manager’s compensation, other accounts under management, and ownership of shares of the Fund.

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Dividends, Capital Gains, and Taxes

Fund Distributions

Each March, June, September, and December, the Fund pays out to shareholders virtually all of the distributions it receives from its REIT investments, less expenses. Distributions may include income, return of capital, and capital gains. The Fund may also realize capital gains on the sale of its REIT investments. Distributions of these gains, if any, are included in the December distribution. In addition, the Fund may occasionally make a supplemental distribution at some other time during the year.

You can receive distributions of income or capital gains or return of capital in cash, or you can have them automatically reinvested in more shares of the Fund. However, if you are investing through an employer-sponsored retirement or savings plan, your distributions will be automatically reinvested in additional Fund shares.

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Basic Tax Points

Vanguard (or your intermediary) expects to send you a statement each February showing the tax status of all of your distributions. (Other Vanguard funds mail their tax statements in January; the Fund mails its statements later because REITs do not provide information on the taxability of their distributions until after the calendar year-end.) In addition, investors in taxable accounts should be aware of the following basic federal income tax points:

• Distributions (other than any return of capital) are taxable to you whether or not you reinvest these amounts in additional Fund shares.

• Distributions declared in December—if paid to you by the end of January—are taxable as if received in December.

• Any dividend distribution or short-term capital gains distribution that you receive is taxable to you as ordinary income. If you are an individual and meet certain holding-period requirements with respect to your Fund shares, you may be eligible for reduced tax rates on “qualified dividend income,” if any, distributed by the Fund. Dividend distributions attributable to the Fund’s REIT investments are generally not eligible for qualified dividend income treatment.

• Any distribution of net long-term capital gains is taxable to you as long-term capital gains, no matter how long you have owned shares in the Fund.

• Capital gains distributions may vary considerably from year to year as a result of the Fund‘s normal investment activities and cash flows.

• A sale or exchange of Fund shares is a taxable event. This means that you may have a capital gain to report as income, or a capital loss to report as a deduction, when you complete your tax return.

• Dividend distributions attributable to the Fund’s REIT investments are generally not eligible for the corporate dividends-received deduction.

• Your cost basis in the Fund will be decreased by the amount of any return of capital that you receive. This, in turn, will affect the amount of any capital gain or loss that you realize when selling or exchanging your Fund shares.

• Return-of-capital distributions generally are not taxable to you until your cost basis has been reduced to zero. If your cost basis is at zero, return-of-capital distributions will be treated as capital gains.

• Any conversion between classes of shares of the same fund is a nontaxable event. By contrast, an exchange between classes of shares of different funds is a taxable event.

Individuals, trusts, and estates whose income exceeds certain threshold amounts are subject to a 3.8% Medicare contribution tax on “net investment income.” Net investment income takes into account distributions paid by the Fund and capital gains from any sale or exchange of Fund shares.

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Dividend distributions and capital gains distributions that you receive, as well as your gains or losses from any sale or exchange of Fund shares, may be subject to state and local income taxes.

This prospectus provides general tax information only. If you are investing through a tax-advantaged account, such as an IRA or an employer-sponsored retirement or savings plan, special tax rules apply. Please consult your tax advisor for detailed information about any tax consequences for you.

General Information

Backup withholding. By law, Vanguard must withhold 28% of any taxable distributions or redemptions from your account if you do not:

• Provide your correct taxpayer identification number.

• Certify that the taxpayer identification number is correct.

• Confirm that you are not subject to backup withholding.

Similarly, Vanguard (or your intermediary) must withhold taxes from your account if the IRS instructs us to do so.

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Foreign investors. Vanguard funds offered for sale in the United States (Vanguard U.S. funds), including the Fund offered in this prospectus, are not widely available outside the United States. Non-U.S. investors should be aware that U.S. withholding and estate taxes and certain U.S. tax reporting requirements may apply to any investments in Vanguard U.S. funds. Foreign investors should visit the Non-U.S. Investors page on our website at vanguard.com for information on Vanguard’s non-U.S. products.

Invalid addresses. If a distribution check mailed to your address of record is returned as undeliverable, Vanguard will automatically reinvest the distribution and all future distributions until you provide us with a valid mailing address. Reinvestments will receive the net asset value calculated on the date of the reinvestment.

Share Price

Share price, also known as net asset value (NAV), is calculated each business day as of the close of regular trading on the New York Stock Exchange (NYSE), generally 4 p.m., Eastern time. Each share class has its own NAV, which is computed by dividing the total assets, minus liabilities, allocated to the share class by the number of Fund shares outstanding for that class. On U.S. holidays or other days when the NYSE is closed, the NAV is not calculated, and the Fund does not sell or redeem shares. However, on those days the value of the Fund’s assets may be affected to the extent that the Fund holds securities that change in value on those days (such as foreign securities that trade on foreign markets that are open).

Stocks held by a Vanguard fund are valued at their market value when reliable market quotations are readily available from the principal exchange or market on which they are traded. Such securities are generally valued at their official closing price, the last reported sales price, or if there were no sales that day, the mean between the closing bid and asking prices. When a fund determines that market quotations either are not readily available or do not accurately reflect the value of a security, the security is priced at its fair value (the amount that the owner might reasonably expect to receive upon the current sale of the security).

The values of any foreign securities held by a fund are converted into U.S. dollars using an exchange rate obtained from an independent third party as of the close of regular trading on the NYSE. The values of any mutual fund shares, including institutional money market fund shares, held by a fund are based on the NAVs of the shares. The values of any ETF shares or closed-end fund shares held by a fund are based on the market value of the shares.

A fund also will use fair-value pricing if the value of a security it holds has been materially affected by events occurring before the fund’s pricing time but after the close of the principal exchange or market on which the security is traded. This most commonly occurs with foreign securities, which may trade on foreign exchanges that

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close many hours before the fund’s pricing time. Intervening events might be company-specific (e.g., earnings report, merger announcement) or country-specific or regional/global (e.g., natural disaster, economic or political news, act of terrorism, interest rate change). Intervening events include price movements in U.S. markets that exceed a specified threshold or that are otherwise deemed to affect the value of foreign securities.

Fair-value pricing may be used for domestic securities—for example, if (1) trading in a security is halted and does not resume before the fund’s pricing time or a security does not trade in the course of a day and (2) the fund holds enough of the security that its price could affect the NAV.

Fair-value prices are determined by Vanguard according to procedures adopted by the board of trustees. When fair-value pricing is employed, the prices of securities used by a fund to calculate the NAV may differ from quoted or published prices for the same securities.

Vanguard fund share prices are published daily on our website at vanguard.com/prices.

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Financial Highlights

The following financial highlights table is intended to help you understand the Institutional Shares‘ financial performance for the periods shown, and certain information reflects financial results for a single Institutional Share. The total returns in the table represent the rate that an investor would have earned or lost each period on an investment in the Institutional Shares (assuming reinvestment of all distributions). This information has been obtained from the financial statements audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, whose report—along with the Fund’s financial statements—is included in the Fund’s most recent annual report to shareholders. You may obtain a free copy of the latest annual or semiannual report by visiting vanguard.com or by contacting Vanguard by telephone or mail.

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