Vanguard U.S. Stock Index Mid-Capitalization Fund Prospectus - Mutual funds… · 2020-04-28 ·...

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Vanguard U.S. Stock Index Mid-Capitalization Fund Prospectus April 28, 2020 Institutional Shares & Institutional Plus Shares Vanguard Extended Market Index Fund Institutional Shares (VIEIX) Vanguard Extended Market Index Fund Institutional Plus Shares (VEMPX) Vanguard Mid-Cap Index Fund Institutional Shares (VMCIX) Vanguard Mid-Cap Index Fund Institutional Plus Shares (VMCPX) See the inside front cover for important information about access to your fund’s annual and semiannual shareholder reports. This prospectus contains financial data for the Funds through the fiscal year ended December 31, 2019. The Securities and Exchange Commission (SEC) has not approved or disapproved these securities or passed upon the adequacy of this prospectus. Any representation to the contrary is a criminal offense.

Transcript of Vanguard U.S. Stock Index Mid-Capitalization Fund Prospectus - Mutual funds… · 2020-04-28 ·...

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Vanguard U.S. Stock Index Mid-Capitalization FundProspectus

April 28, 2020

Institutional Shares & Institutional Plus Shares

Vanguard Extended Market Index Fund Institutional Shares (VIEIX)

Vanguard Extended Market Index Fund Institutional Plus Shares (VEMPX)

Vanguard Mid-Cap Index Fund Institutional Shares (VMCIX)

Vanguard Mid-Cap Index Fund Institutional Plus Shares (VMCPX)

See the inside front cover for important information about access to yourfund’s annual and semiannual shareholder reports.

This prospectus contains financial data for the Funds through the fiscal year ended December 31, 2019.

The Securities and Exchange Commission (SEC) has not approved or disapproved thesesecurities or passed upon the adequacy of this prospectus. Any representation to the contrary isa criminal offense.

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Important information about access to shareholder reports

Beginning on January 1, 2021, as permitted by regulations adopted by theSEC, paper copies of your fund’s annual and semiannual shareholder reportswill no longer be sent to you by mail, unless you specifically request them.Instead, you will be notified by mail each time a report is posted on thewebsite and will be provided with a link to access the report.

If you have already elected to receive shareholder reports electronically, youwill not be affected by this change and do not need to take any action. You mayelect to receive shareholder reports and other communications from the fundelectronically by contacting your financial intermediary (such as a broker-dealeror bank) or, if you invest directly with the fund, by calling Vanguard at one ofthe phone numbers on the back cover of this prospectus or by logging on tovanguard.com.

You may elect to receive paper copies of all future shareholder reports free ofcharge. If you invest through a financial intermediary, you can contact theintermediary to request that you continue to receive paper copies. If you investdirectly with the fund, you can call Vanguard at one of the phone numbers onthe back cover of this prospectus or log on to vanguard.com. Your election toreceive paper copies will apply to all the funds you hold through anintermediary or directly with Vanguard.

Contents

Vanguard Fund Summaries

Extended Market Index Fund 1

Mid-Cap Index Fund 6

Investing in Index Funds 12

More on the Funds 13

The Funds and Vanguard 18

Investment Advisor 19

Dividends, Capital Gains, and Taxes 20

Share Price 23

Financial Highlights 25

Investing With Vanguard 29

Purchasing Shares 29

Converting Shares 32

Redeeming Shares 34

Exchanging Shares 38

Frequent-Trading Limitations 39

Other Rules You Should Know 41

Fund and Account Updates 45

Employer-Sponsored Plans 46

Contacting Vanguard 48

Additional Information 48

Glossary of Investment Terms 50

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Vanguard Extended Market Index Fund

Investment ObjectiveThe Fund seeks to track the performance of a benchmark index that measuresthe investment return of small- and mid-capitalization stocks.

Fees and ExpensesThe following table describes the fees and expenses you may pay if you buy andhold Institutional Shares or Institutional Plus Shares of the Fund.

Shareholder Fees(Fees paid directly from your investment)

Institutional Shares Institutional Plus SharesSales Charge (Load) Imposed on Purchases None NonePurchase Fee None NoneSales Charge (Load) Imposed on ReinvestedDividends None NoneRedemption Fee None None

Annual Fund Operating Expenses(Expenses that you pay each year as a percentage of the value of your investment)

Institutional Shares Institutional Plus SharesManagement Fees 0.04% 0.03%12b-1 Distribution Fee None NoneOther Expenses 0.01% 0.01%Total Annual Fund Operating Expenses 0.05% 0.04%

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Examples

The following examples are intended to help you compare the cost of investingin the Fund’s Institutional Shares or Institutional Plus Shares with the cost ofinvesting in other mutual funds. They illustrate the hypothetical expenses thatyou would incur over various periods if you were to invest $10,000 in the Fund’sshares. These examples assume that the shares provide a return of 5% eachyear and that total annual fund operating expenses remain as stated in thepreceding table. You would incur these hypothetical expenses whether or notyou were to redeem your investment at the end of the given period. Althoughyour actual costs may be higher or lower, based on these assumptions yourcosts would be:

1 Year 3 Years 5 Years 10 YearsInstitutional Shares $5 $16 $28 $64Institutional Plus Shares $4 $13 $23 $51

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sellssecurities (or “turns over” its portfolio). A higher portfolio turnover rate mayindicate higher transaction costs and may result in more taxes when Fundshares are held in a taxable account. These costs, which are not reflected inannual fund operating expenses or in the previous expense examples, reducethe Fund’s performance. During the most recent fiscal year, the Fund’s portfolioturnover rate was 13% of the average value of its portfolio.

Principal Investment StrategiesThe Fund employs an indexing investment approach designed to track theperformance of the Standard & Poor‘s Completion Index, a broadly diversifiedindex of stocks of small and mid-size U.S. companies. The S&P Completion Indexcontains all of the U.S. common stocks regularly traded on the New York StockExchange and the Nasdaq over-the-counter market, except those stocks includedin the S&P 500 Index. The Fund invests by sampling the Index, meaning that itholds a broadly diversified collection of securities that, in the aggregate,approximates the full Index in terms of key characteristics. These characteristicsinclude industry weightings and market capitalization, as well as certain financialmeasures, such as price/earnings ratio and dividend yield.

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Principal RisksAn investment in the Fund could lose money over short or long periods of time.You should expect the Fund’s share price and total return to fluctuate within awide range. The Fund is subject to the following risks, which could affect theFund’s performance:

• 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 periodsof falling prices. The Fund’s target index tracks a subset of the U.S. stock market,which could cause the Fund to perform differently from the overall stock market.In addition, the Fund’s target index may, at times, become focused in stocks of aparticular market sector, which would subject the Fund to proportionately higherexposure to the risks of that sector.

• Investment style risk, which is the chance that returns from small- and mid-capitalization stocks will trail returns from the overall stock market. Historically,small- and mid-cap stocks have been more volatile in price than the large-capstocks that dominate the overall market, and they often perform quite differently.The stock prices of small and mid-size companies tend to experience greatervolatility because, among other things, these companies tend to be moresensitive to changing economic conditions.

• Index sampling risk, which is the chance that the securities selected for theFund, in the aggregate, will not provide investment performance matching thatof the Fund’s target index. Index sampling risk for the Fund is expected tobe low.

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

Annual Total ReturnsThe following bar chart and table are intended to help you understand the risksof investing in the Fund. The bar chart shows how the performance of the Fund‘sInstitutional Shares has varied from one calendar year to another over theperiods shown. The table shows how the average annual total returns of theshare classes presented compare with those of the Fund’s target index whichhas investment characteristics similar to those of the Fund. Keep in mind thatthe Fund’s past performance (before and after taxes) does not indicate how theFund will perform in the future. Updated performance information is available onour website at vanguard.com/performance or by calling Vanguard toll-free at800-662-7447.

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Annual Total Returns — Vanguard Extended Market Index Fund Institutional Shares

2010 2011 2012 2013 2014 2015 2016 2017 2018 2019

0%10%20%30%40%50%

-10%-20%

27.59

–3.57

18.50

38.42

7.56

–3.24

16.15 18.12

–9.35

28.05

During the periods shown in the bar chart, the highest and lowest returns for acalendar quarter were:

Total Return QuarterHighest 15.99% March 31, 2019Lowest -21.01% September 30, 2011

Average Annual Total Returns for Periods Ended December 31, 2019

1 Year 5 Years 10 YearsVanguard Extended Market Index Fund InstitutionalShares

Return Before Taxes 28.05% 9.03% 12.83%Return After Taxes on Distributions 27.54 8.58 12.43Return After Taxes on Distributions and Sale of Fund Shares 16.78 6.99 10.63Standard & Poor’s Completion Index(reflects no deduction for fees, expenses, or taxes) 27.95% 8.90% 12.71%

1 Year 5 Years

SinceInception(Jan. 14,2011)

Vanguard Extended Market Index Fund Institutional PlusShares

Return Before Taxes 28.07% 9.05% 10.98%Standard & Poor’s Completion Index(reflects no deduction for fees, expenses, or taxes) 27.95% 8.90% 10.84%

Actual after-tax returns depend on your tax situation and may differ from thoseshown in the preceding table. When after-tax returns are calculated, it isassumed that the shareholder was in the highest individual federal marginalincome tax bracket at the time of each distribution of income or capital gains orupon redemption. State and local income taxes are not reflected in thecalculations. Please note that after-tax returns are shown only for the InstitutionalShares and may differ for each share class. After-tax returns are not relevant for a

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shareholder who holds fund shares in a tax-deferred account, such as anindividual retirement account or a 401(k) plan. Also, figures captioned ReturnAfter Taxes on Distributions and Sale of Fund Shares may be higher than otherfigures for the same period if a capital loss occurs upon redemption and resultsin an assumed tax deduction for the shareholder.

Investment AdvisorThe Vanguard Group, Inc. (Vanguard)

Portfolio Managers

Donald M. Butler, CFA, Principal of Vanguard. He has managed the Fund since1997 (co-managed since 2016).

William A. Coleman, CFA, Portfolio Manager at Vanguard. He has co-managedthe Fund since 2017.

Purchase and Sale of Fund SharesYou 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 bytelephone (800-662-2739). The minimum investment amount required to openand maintain a Fund account for Institutional Shares or Institutional Plus Sharesis $5 million or $100 million, respectively. The minimum investment amountrequired to add to an existing Fund account is generally $1. If you are investingthrough an employer-sponsored retirement or savings plan, your planadministrator or your benefits office can provide you with detailed information onhow you can invest through your plan.

Tax InformationThe Fund’s distributions may be taxable as ordinary income or capital gain. If youare investing through a tax-advantaged account, such as an IRA or anemployer-sponsored retirement or savings plan, special tax rules apply.

Payments to Financial IntermediariesThe Fund and its investment advisor do not pay financial intermediaries for salesof Fund shares.

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Vanguard Mid-Cap Index Fund

Investment ObjectiveThe Fund seeks to track the performance of a benchmark index that measuresthe investment return of mid-capitalization stocks.

Fees and ExpensesThe following table describes the fees and expenses you may pay if you buy andhold Institutional Shares or Institutional Plus Shares of the Fund.

Shareholder Fees(Fees paid directly from your investment)

Institutional Shares Institutional Plus SharesSales Charge (Load) Imposed on Purchases None NonePurchase Fee None NoneSales Charge (Load) Imposed on ReinvestedDividends None NoneRedemption Fee None None

Annual Fund Operating Expenses(Expenses that you pay each year as a percentage of the value of your investment)

Institutional Shares Institutional Plus SharesManagement Fees 0.04% 0.03%12b-1 Distribution Fee None NoneOther Expenses 0.00% 0.00%Total Annual Fund Operating Expenses 0.04% 0.03%

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Examples

The following examples are intended to help you compare the cost of investingin the Fund’s Institutional Shares or Institutional Plus Shares with the cost ofinvesting in other mutual funds. They illustrate the hypothetical expenses thatyou would incur over various periods if you were to invest $10,000 in the Fund’sshares. These examples assume that the shares provide a return of 5% eachyear and that total annual fund operating expenses remain as stated in thepreceding table. You would incur these hypothetical expenses whether or notyou were to redeem your investment at the end of the given period. Althoughyour actual costs may be higher or lower, based on these assumptions yourcosts would be:

1 Year 3 Years 5 Years 10 YearsInstitutional Shares $4 $13 $23 $51Institutional Plus Shares $3 $10 $17 $39

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sellssecurities (or “turns over” its portfolio). A higher portfolio turnover rate mayindicate higher transaction costs and may result in more taxes when Fundshares are held in a taxable account. These costs, which are not reflected inannual fund operating expenses or in the previous expense examples, reducethe Fund’s performance. During the most recent fiscal year, the Fund’s portfolioturnover rate was 15% of the average value of its portfolio.

Principal Investment StrategiesThe Fund employs an indexing investment approach designed to track theperformance of the CRSP US Mid Cap Index, a broadly diversified index ofstocks of mid-size U.S. companies. The Fund attempts to replicate the targetindex by investing all, or substantially all, of its assets in the stocks that make upthe Index, holding each stock in approximately the same proportion as itsweighting in the Index.

Principal RisksAn investment in the Fund could lose money over short or long periods of time.You should expect the Fund’s share price and total return to fluctuate within awide range. The Fund is subject to the following risks, which could affect theFund’s performance:

• 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 periodsof falling prices. The Fund’s target index tracks a subset of the U.S. stock market,

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which could cause the Fund to perform differently from the overall stock market.In addition, the Fund’s target index may, at times, become focused in stocks of aparticular market sector, which would subject the Fund to proportionately higherexposure to the risks of that sector.

• Investment style risk, which is the chance that returns from mid-capitalizationstocks will trail returns from the overall stock market. Historically, mid-cap stockshave been more volatile in price than the large-cap stocks that dominate theoverall market, and they often perform quite differently. The stock prices ofmid-size companies tend to experience greater volatility because, among otherthings, these companies tend to be more sensitive to changingeconomic conditions.

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

Annual Total ReturnsThe following bar chart and table are intended to help you understand the risksof investing in the Fund. The bar chart shows how the performance of the Fund‘sInstitutional Shares has varied from one calendar year to another over theperiods shown. The table shows how the average annual total returns of theshare classes presented compare with those of the Fund’s target index andother comparative indexes, which have investment characteristics similar tothose of the Fund. The Spliced Mid Cap Index reflects the performance of theMSCI US Mid Cap 450 Index through January 30, 2013, and the CRSP US MidCap Index thereafter. Keep in mind that the Fund’s past performance (before andafter taxes) does not indicate how the Fund will perform in the future. Updatedperformance information is available on our website atvanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

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Annual Total Returns — Vanguard Mid-Cap Index Fund Institutional Shares

2010 2011 2012 2013 2014 2015 2016 2017 2018 2019

0%10%20%30%40%50%

-10%-20%

25.67

–1.96

16.01

35.17

13.78

–1.33

11.2319.29

–9.24

31.04

During the periods shown in the bar chart, the highest and lowest returns for acalendar quarter were:

Total Return QuarterHighest 16.78% March 31, 2019Lowest -19.13% September 30, 2011

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Average Annual Total Returns for Periods Ended December 31, 2019

1 Year 5 Years 10 YearsVanguard Mid-Cap Index Fund Institutional Shares

Return Before Taxes 31.04% 9.26% 13.09%Return After Taxes on Distributions 30.50 8.82 12.72Return After Taxes on Distributions and Sale of Fund Shares 18.63 7.22 10.91Comparative Indexes(reflect no deduction for fees, expenses, or taxes)MSCI US Mid Cap 450 Index 30.61% 10.08% 13.59%Spliced Mid Cap Index 31.09 9.29 13.13CRSP US Mid Cap Index 31.09 9.29 —

1 Year 5 Years

SinceInception(Dec. 15,2010)

Vanguard Mid-Cap Index Fund Institutional Plus Shares

Return Before Taxes 31.06% 9.28% 12.00%Comparative Indexes(reflect no deduction for fees, expenses, or taxes)MSCI US Mid Cap 450 Index 30.61% 10.08% 12.52%Spliced Mid Cap Index 31.09 9.29 12.02CRSP US Mid Cap Index 31.09 9.29 —

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

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Investment AdvisorThe Vanguard Group, Inc. (Vanguard)

Portfolio Managers

Donald M. Butler, CFA, Principal of Vanguard. He has managed the Fund since itsinception in 1998 (co-managed since 2016).

Michael A. Johnson, Portfolio Manager at Vanguard. He has co-managed theFund since 2016.

Purchase and Sale of Fund SharesYou 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 bytelephone (800-662-2739). The minimum investment amount required to openand maintain a Fund account for Institutional Shares or Institutional Plus Sharesis $5 million or $100 million, respectively. The minimum investment amountrequired to add to an existing Fund account is generally $1. If you are investingthrough an employer-sponsored retirement or savings plan, your planadministrator or your benefits office can provide you with detailed information onhow you can invest through your plan.

Tax InformationThe Fund’s distributions may be taxable as ordinary income or capital gain. If youare investing through a tax-advantaged account, such as an IRA or anemployer-sponsored retirement or savings plan, special tax rules apply.

Payments to Financial IntermediariesThe Fund and its investment advisor do not pay financial intermediaries for salesof Fund shares.

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Investing in Index Funds

What Is Indexing?Indexing is an investment strategy for tracking the performance of a specifiedmarket benchmark, or “index.” An index is a group of securities whose overallperformance is used as a standard to measure the investment performance of aparticular market. There are many types of indexes. Some represent entiremarkets—such as the U.S. stock market or the U.S. bond market. Other indexescover market segments—such as small-capitalization stocks or short-termbonds. One cannot invest directly in an index.

The index sponsor determines the securities to include in the index and theweighting of each security in the index. Under normal circumstances, the indexsponsor will rebalance an index on a regular schedule. An index sponsor maycarry out additional ad hoc index rebalances, delay or cancel a scheduledrebalance. Generally, the index sponsor does not provide any warranty, or acceptany liability, with respect to the quality, accuracy, or completeness of either thetarget index or its related data. Errors made by the index sponsor may occurfrom time to time and may not be identified by the index sponsor for a period oftime or at all. Vanguard does not provide any warranty or guarantee against sucherrors. Therefore, the gains, losses, or costs associated with the index sponsor’serrors will generally be borne by the index fund and its shareholders.

An index fund seeks to hold all, or a representative sample, of the securities thatmake up its target index. Index funds attempt to mirror the performance of thetarget index, for better or worse. However, an index fund generally does notperform exactly like its target index. For example, index funds have operatingexpenses and transaction costs. Market indexes do not, and therefore they willusually have a slight performance advantage over funds that track them. Theability of an index fund to match its performance to that of its target index canalso be impacted by, among other things, the timing and size of cash flows andthe size of the fund. Market disruptions and regulatory restrictions could alsohave an adverse effect on a fund’s ability to adjust its exposure to the requiredlevels in order to track the index.

Index funds typically have the following characteristics:

• Variety of investments. Index funds generally invest in the securities of avariety of companies and industries.

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

• Low cost. Index funds are generally inexpensive to run compared with activelymanaged funds. They have low or no research costs and typically keep tradingactivity— and thus brokerage commissions and other transaction costs—to aminimum compared with actively managed funds.

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More on the Funds

This prospectus describes the principal risks you would face as a Fundshareholder. It is important to keep in mind one of the main principles ofinvesting: generally, the higher the risk of losing money, the higher the potentialreward. The reverse, also, is generally true: the lower the risk, the lower thepotential reward. As you consider an investment in any mutual fund, you shouldtake into account your personal tolerance for fluctuations in the securitiesmarkets. Look for this symbol throughout the prospectus. It is used tomark detailed information about the more significant risks that you wouldconfront as a Fund shareholder. To highlight terms and concepts important tomutual fund investors, we have provided Plain Talk® explanations along the way.Reading the prospectus will help you decide whether a Fund is the rightinvestment for you. We suggest that you keep this prospectus forfuture reference.

Share Class OverviewThis prospectus offers the Funds’ Institutional Shares and Institutional PlusShares, which are generally for investors who invest a minimum of $5 millionand $100 million, respectively. A separate prospectus offers the Funds‘ InvestorShares and Admiral™ Shares, which generally have investment minimums of$3,000. Another prospectus offers Institutional Select Shares for the ExtendedMarket Index Fund, which are generally for investors who invest a minimum of$3 billion. In addition, each Fund issues ETF Shares (an exchange-traded class ofshares), which are also offered through a separate prospectus.

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

Plain Talk About Costs of Investing

Costs are an important consideration in choosing a mutual fund. That isbecause you, as a shareholder, pay a proportionate share of the costs ofoperating a fund and any transaction costs incurred when the fund buys orsells securities. These costs can erode a substantial portion of the grossincome or the capital appreciation a fund achieves. Even seemingly smalldifferences in expenses can, over time, have a dramatic effect on afund’s performance.

The following sections explain the principal investment strategies and policiesthat each Fund uses in pursuit of its objective. The Funds’ board of trustees,which oversees each Fund’s management, may change investment strategies orpolicies in the interest of shareholders without a shareholder vote, unless those

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strategies or policies are designated as fundamental. Under normalcircumstances, each Fund will invest at least 80% of its assets in the stocks thatmake up its target index. A Fund may change its 80% policy only upon 60 days‘notice to shareholders.

Market Exposure

Each Fund is subject to stock market risk, which is the chance that stockprices overall will decline. Stock markets tend to move in cycles, withperiods of rising prices and periods of falling prices. Each Fund‘s targetindex tracks a subset of the U.S. stock market, which could cause theFund to perform differently from the overall stock market. In addition,each Fund‘s target index may, at times, become focused in stocks of aparticular market sector, which would subject the Fund to proportionatelyhigher exposure to the risks of that sector.

Stocks of publicly traded companies are often classified according to marketcapitalization, which is the market value of a company’s outstanding shares.These classifications typically include small-cap, mid-cap, and large-cap. It isimportant to understand that there are no “official” definitions of small-, mid-,and large-cap, even among Vanguard fund advisors, and that marketcapitalization ranges can change over time.

The asset-weighted median market capitalization of each Fund’s stock holdingsas of December 31, 2019, was:

Vanguard Fund Asset-Weighted MedianMarket Capitalization

Extended Market Index Fund $5.1 billionMid-Cap Index Fund 17.0

Each Fund is subject to investment style risk, which is the chance thatreturns from the types of stocks in which the Fund invests will trailreturns from the overall stock market. Historically, small- andmid-capitalization stocks have been more volatile in price than thelarge-cap stocks that dominate the overall market, and they often performquite differently. The stock prices of small and mid-size companies tendto experience greater volatility because, among other things, thesecompanies tend to be more sensitive to changing economic conditions.

Security SelectionEach Fund attempts to track the investment performance of a benchmark indexthat measures the return of a particular market segment. The Extended MarketIndex Fund uses a sampling method of indexing, meaning that the Fund’sadvisor, using computer programs, generally selects from the target index a

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representative sample of securities that will resemble the target index in termsof key risk factors and other characteristics. These include industry weightings,market capitalization, and other financial characteristics of stocks.

The Extended Market Index Fund is subject to index sampling risk, whichis the chance that the securities selected for the Fund, in the aggregate,will not provide investment performance matching that of the Fund’starget index. Index sampling risk for the Fund is expected to be low.

The Mid-Cap Index Fund uses the replication method of indexing, meaning thatthe Fund generally holds the same stocks as its target index and inapproximately the same proportions.

Other Investment Policies and RisksEach Fund reserves the right to substitute a different index for the index itcurrently tracks if the current index is discontinued, if the Fund’s agreement withthe sponsor of its target index is terminated, or for any other reason determinedin good faith by the Fund’s board of trustees. In any such instance, the substituteindex would represent the same market segment as the current index.

Each Fund may invest in foreign securities to the extent necessary to carry outits investment strategy of holding all, or a representative sample of the stocksthat make up the index it tracks. It is not expected that any Fund will invest morethan 5% of its assets in foreign securities.

To track their target indexes as closely as possible, the Funds attempt to remainfully invested in stocks. To help stay fully invested and to reduce transactioncosts, the Funds may invest, to a limited extent, in derivatives, including equityfutures. The Funds may also use derivatives such as total return swaps to obtainexposure to a stock, a basket of stocks, or an index. Generally speaking, aderivative is a financial contract whose value is based on the value of a financialasset (such as a stock, a bond, or a currency), a physical asset (such as gold, oil,or wheat), a market index, or a reference rate. Investments in derivatives maysubject the Funds to risks different from, and possibly greater than, those ofinvestments directly in the underlying securities or assets. The Funds will notuse derivatives for speculation or for the purpose of leveraging (magnifying)investment returns.

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Cash ManagementEach Fund’s daily cash balance may be invested in Vanguard Market LiquidityFund and/or Vanguard Municipal Cash Management Fund (each, a CMT Fund),which are low-cost money market funds. When investing in a CMT Fund, eachFund bears its proportionate share of the expenses of the CMT Fund in which itinvests. Vanguard receives no additional revenue from Fund assets invested in aCMT Fund.

Methods Used to Meet Redemption RequestsUnder normal circumstances, each Fund typically expects to meet redemptionswith positive cash flows. When this is not an option, each Fund seeks tomaintain its risk exposure by selling a cross section of the Fund’s holdings tomeet redemptions, while also factoring in transaction costs. Additionally, a Fundmay work with larger clients to implement their redemptions in a manner that isleast disruptive to the portfolio; see “Potentially disruptive redemptions” underRedeeming Shares in the Investing With Vanguard section.

Under certain circumstances, including under stressed market conditions, thereare additional tools that each Fund may use in order to meet redemptions,including advancing the settlement of market trades with counterparties tomatch investor redemption payments or delaying settlement of an investor’stransaction to match trade settlement within regulatory requirements. A Fundmay also suspend payment of redemption proceeds for up to seven days; see“Emergency circumstances” under Redeeming Shares in the Investing WithVanguard section. Additionally under these unusual circumstances, a Fund mayborrow money (subject to certain regulatory conditions and if available underboard-approved procedures) through an interfund lending facility or through abank line-of-credit, including a joint committed credit facility, in order to meetredemption requests.

Temporary Investment MeasuresEach Fund may temporarily depart from its normal investment policies andstrategies when an advisor believes that doing so is in the Fund’s best interest,so long as the strategy or policy employed is consistent with the Fund’sinvestment objective. For instance, a Fund may invest beyond its normal limits inderivatives or exchange-traded funds that are consistent with the Fund’sinvestment objective when those instruments are more favorably priced orprovide needed liquidity, as might be the case when the Fund receives largecash flows that it cannot prudently invest immediately.

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Frequent Trading or Market-TimingBackground. Some investors try to profit from strategies involving frequenttrading of mutual fund shares, such as market-timing. For funds holding foreignsecurities, investors may try to take advantage of an anticipated differencebetween the price of the fund’s shares and price movements in overseasmarkets, a practice also known as time-zone arbitrage. Investors also may try toengage in frequent trading of funds holding investments such as small-capstocks and high-yield bonds. As money is shifted into and out of a fund by ashareholder engaging in frequent trading, the fund incurs costs for buying andselling securities, resulting in increased brokerage and administrative costs.These costs are borne by all fund shareholders, including the long-term investorswho do not generate the costs. In addition, frequent trading may interfere withan advisor’s ability to efficiently manage the fund.

Policies to address frequent trading. The Vanguard funds (other than moneymarket funds and short-term bond funds, but including Vanguard Short-TermInflation-Protected Securities Index Fund) do not knowingly accommodatefrequent trading. The board of trustees of each Vanguard fund (other than moneymarket funds and short-term bond funds, but including Vanguard Short-TermInflation-Protected Securities Index Fund) has adopted policies and proceduresreasonably designed to detect and discourage frequent trading and, in somecases, to compensate the fund for the costs associated with it. These policiesand procedures do not apply to ETF Shares because frequent trading in ETFShares generally does not disrupt portfolio management or otherwise harm fundshareholders. Although there is no assurance that Vanguard will be able todetect or prevent frequent trading or market-timing in all circumstances, thefollowing policies have been adopted to address these issues:

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

• Each Vanguard fund (other than money market funds and short-term bondfunds, but including Vanguard Short-Term Inflation-Protected Securities IndexFund) generally prohibits, except as otherwise noted in the Investing WithVanguard section, an investor’s purchases or exchanges into a fund account for30 calendar days after the investor has redeemed or exchanged out of thatfund account.

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

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

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

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

Turnover RateAlthough the Funds generally seek to invest for the long term, each Fund maysell securities regardless of how long they have been held. Generally, an indexfund sells securities in response to redemption requests from shareholders ofconventional (not exchange-traded) shares or to changes in the composition ofits target index. Turnover rates for mid-cap and small-cap stock index funds tendto be higher than for large-cap stock index funds (although still relatively low,compared with actively managed stock funds) because the indexes they trackare more likely to change as a result of companies merging, growing, or failing.The Financial Highlights section of this prospectus shows historical turnoverrates for the Funds. A turnover rate of 100%, for example, would mean that aFund had sold and replaced securities valued at 100% of its net assets within aone-year period. In general, the greater the turnover rate, the greater the impacttransaction costs will have on a fund’s return. Also, funds with high turnoverrates may be more likely to generate capital gains, including short-term capitalgains, that must be distributed to shareholders and will be taxable toshareholders investing through a taxable account.

The Funds and Vanguard

Each Fund is a member of The Vanguard Group, a family of over 200 funds. All ofthe funds that are members of The Vanguard Group (other than funds of funds)share in the expenses associated with administrative services and businessoperations, such as personnel, office space, and equipment.

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

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Plain Talk About Vanguard’s Unique Corporate Structure

The Vanguard Group is owned jointly by the funds it oversees and thusindirectly by the shareholders in those funds. Most other mutual funds areoperated by management companies that are owned by third parties—eitherpublic or private stockholders—and not by the funds they serve.

Investment Advisor

The Vanguard Group, Inc., P.O. Box 2600, Valley Forge, PA 19482, which beganoperations in 1975, serves as advisor to the Funds through its Equity IndexGroup. As of December 31, 2019, Vanguard served as advisor for approximately$5 trillion in assets. Vanguard provides investment advisory services to theFunds pursuant to the Funds’ Service Agreement and subject to the supervisionand oversight of the trustees and officers of the Funds.

For the fiscal year ended December 31, 2019, the advisory expensesrepresented an effective annual rate of 0.01% of each Fund’s average net assets.

Under the terms of an SEC exemption, the Funds‘ board of trustees may,without prior approval from shareholders, change the terms of an advisoryagreement with a third-party investment advisor or hire a new third-partyinvestment advisor—either as a replacement for an existing advisor or as anadditional advisor. Any significant change in a Fund’s advisory arrangements willbe communicated to shareholders in writing. As the Funds‘ sponsor and overallmanager, Vanguard may provide investment advisory services to a Fund at anytime. Vanguard may also recommend to the board of trustees that an advisor behired, terminated, or replaced or that the terms of an existing advisoryagreement be revised. The Funds have filed an application seeking a similar SECexemption with respect to investment advisors that are wholly ownedsubsidiaries of Vanguard. If the exemption is granted, the Funds may rely on thenew SEC relief.

For a discussion of why the board of trustees approved each Fund’s investmentadvisory arrangement, see the most recent semiannual report to shareholderscovering the fiscal period ended June 30.

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

Donald M. Butler, CFA, Principal of Vanguard. He has been with Vanguard since1992; has managed investment portfolios including the Extended Market IndexFund, since 1997 (co-managed since 2016); and has managed the Mid-Cap IndexFund since its inception in 1998 (co-managed since 2016). Education: B.S.B.A.,Shippensburg University.

William A. Coleman, CFA, Portfolio Manager at Vanguard. He has worked ininvestment management since joining Vanguard in 2006 and has co-managedthe Extended Market Index Fund since 2017. Education: B.S., King’s College;M.S., Saint Joseph’s University.

Michael A. Johnson, Portfolio Manager at Vanguard. He has been with Vanguardsince 1999, has managed investment portfolios since 2010, has worked ininvestment management since 2007, and has co-managed the Mid-Cap IndexFund since 2016. Education: B.S.B.A., Shippensburg University.

The Funds’ Statement of Additional Information provides information about eachportfolio manager’s compensation, other accounts under management, andownership of shares of the Funds.

Dividends, Capital Gains, and Taxes

Fund DistributionsEach Fund distributes to shareholders virtually all of its net income (interest anddividends, less expenses) as well as any net short-term or long-term capitalgains realized from the sale of its holdings. Income dividends generally aredistributed quarterly in March, June, September, and December; capital gainsdistributions, if any, generally occur annually in December. In addition, each Fundmay occasionally make a supplemental distribution at some other time duringthe year. You can receive distributions of income or capital gains in cash, or youcan have them automatically reinvested in more shares of the Fund. However, ifyou are investing through an employer-sponsored retirement or savings plan,your distributions will be automatically reinvested in additional Fund shares.

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Plain Talk About Distributions

As a shareholder, you are entitled to your portion of a fund’s income frominterest as well as capital gains from the fund’s sale of investments. Incomeconsists of interest the fund earns from its money market and bondinvestments. The portion of such dividends that is exempt from federalincome tax will be designated as “exempt-interest dividends.” Capital gainsare realized whenever the fund sells securities for higher prices than it paidfor them. These capital gains are either short-term or long-term, dependingon whether the fund held the securities for one year or less or for more thanone year.

Basic Tax PointsInvestors in taxable accounts should be aware of the following basic federalincome tax points:

• Distributions are taxable to you whether or not you reinvest these amounts inadditional Fund shares.

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

• Any dividend distribution or short-term capital gains distribution that youreceive is taxable to you as ordinary income. If you are an individual and meetcertain holding-period requirements with respect to your Fund shares, you maybe eligible for reduced tax rates on “qualified dividend income,” if any, distributedby the Fund.

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

• Capital gains distributions may vary considerably from year to year as a resultof the Funds’ normal investment activities and cash flows.

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

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

• Vanguard (or your intermediary) will send you a statement each year showingthe tax status of all of your distributions.

Individuals, trusts, and estates whose income exceeds certain thresholdamounts are subject to a 3.8% Medicare contribution tax on “net investment

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income.” Net investment income takes into account distributions paid by theFund and capital gains from any sale or exchange of Fund shares.

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

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

Plain Talk About Buying a Dividend

Unless you are tax-exempt investor or investing through a tax-advantagedaccount (such as an IRA or an employer-sponsored retirement or savingsplan), you should consider avoiding a purchase of fund shares shortly beforethe fund makes a distribution, because doing so can cost you money intaxes. This is known as “buying a dividend.” For example: On December 15,you invest $5,000, buying 250 shares for $20 each. If the fund pays adistribution of $1 per share on December 16, its share price will drop to $19(not counting market change). You still have only $5,000 (250 shares x $19 =$4,750 in share value, plus 250 shares x $1 = $250 in distributions), but youowe tax on the $250 distribution you received—even if you reinvest it inmore shares. To avoid buying a dividend, check a fund’s distribution schedulebefore you invest.

General InformationBackup withholding. By law, Vanguard must withhold 24% of any taxabledistributions 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 accountif the IRS instructs us to do so. The backup withholding rules may also apply todistributions that are designated as exempt-interest dividends.

Foreign investors. Vanguard funds offered for sale in the United States(Vanguard U.S. funds), including the Funds offered in this prospectus, are notwidely available outside the United States. Non-U.S. investors should be aware

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that U.S. withholding and estate taxes and certain U.S. tax reportingrequirements may apply to any investments in Vanguard U.S. funds. Foreigninvestors should visit the non-U.S. investors page on our website atvanguard.com for information on Vanguard’s non-U.S. products.

Invalid addresses. If a dividend distribution or capital gains distribution checkmailed to your address of record is returned as undeliverable, Vanguard willautomatically reinvest the distribution and all future distributions until you provideus with a valid mailing address. Reinvestments will receive the net asset valuecalculated on the date of the reinvestment.

Share Price

Share price, also known as net asset value (NAV), is calculated as of the close ofregular trading on the New York Stock Exchange (NYSE), generally 4 p.m.,Eastern time, on each day that the NYSE is open for business (a business day).In the rare event the NYSE experiences unanticipated disruptions and isunavailable at the close of the trading day, a Fund reserves the right to treat suchday as a business day and calculate NAVs as of the close of regular trading onthe Nasdaq (or another alternate exchange if the Nasdaq is unavailable, asdetermined at Vanguard’s discretion), generally 4 p.m., Eastern time. Each shareclass has its own NAV, which is computed by dividing the total assets, minusliabilities, allocated to the share class by the number of Fund shares outstandingfor that class. On U.S. holidays or other days when the NYSE is closed, the NAVis not calculated, and the Funds do not sell or redeem shares. However, onthose days the value of a Fund’s assets may be affected to the extent that theFund holds securities that change in value on those days (such as foreignsecurities that trade on foreign markets that are open).

Stocks held by a Vanguard fund are valued at their market value when reliablemarket quotations are readily available from the principal exchange or market onwhich they are traded. Such securities are generally valued at their official closingprice, the last reported sales price, or if there were no sales that day, the meanbetween the closing bid and asking prices. When a fund determines that marketquotations either are not readily available or do not accurately reflect the value ofa security, the security is priced at its fair value (the amount that the ownermight 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. dollarsusing an exchange rate obtained from an independent third party as of the closeof regular trading on the NYSE. The values of any mutual fund shares, including

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institutional money market fund shares, held by a fund are based on the NAVs ofthe shares. The values of any ETF shares or closed-end fund shares held by afund 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 beenmaterially affected by events occurring before the fund’s pricing time but afterthe close of the principal exchange or market on which the security is traded.This most commonly occurs with foreign securities, which may trade on foreignexchanges that close many hours before the fund’s pricing time. Interveningevents might be company-specific (e.g., earnings report, merger announcement)or country-specific or regional/global (e.g., natural disaster, economic or politicalnews, act of terrorism, interest rate change). Intervening events include pricemovements in U.S. markets that exceed a specified threshold or that areotherwise deemed to affect the value of foreign securities.

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

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

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

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Financial Highlights

Financial highlights information is intended to help you understand a fund’sperformance for the past five years (or, if shorter, its period of operations).Certain information reflects financial results for a single fund share. Total returnrepresents the rate that an investor would have earned or lost each period on aninvestment in a fund or share class the Fund (assuming reinvestment of alldistributions). This information has been obtained from the financial statementsaudited by PricewaterhouseCoopers LLP, an independent registered publicaccounting firm, whose report, along with fund financial statements, is includedin a fund’s most recent annual report to shareholders. You may obtain a free copyof a fund’s latest annual or semiannual report, which is available upon request.

Vanguard Extended Market Index Fund Institutional Shares

Year Ended December 31,For a Share Outstanding Throughout Each Period 2019 2018 2017 2016 2015Net Asset Value, Beginning of Period $75.69 $84.75 $72.72 $63.58 $66.60

Investment Operations

Net Investment Income 1.2391 1.3191 1.0851 1.018 0.899Net Realized and Unrealized Gain (Loss) onInvestments

19.925 (9.113) 12.018 9.175 (3.050)

Total from Investment Operations 21.164 (7.794) 13.103 10.193 (2.151)Distributions

Dividends from Net Investment Income (1.254) (1.266) (1.073) (1.053) (0.869)Distributions from Realized Capital Gains — — — — —Total Distributions (1.254) (1.266) (1.073) (1.053) (0.869)Net Asset Value, End of Period $95.60 $75.69 $84.75 $72.72 $63.58

Total Return 28.05% –9.35% 18.12% 16.15% –3.24%

Ratios/Supplemental Data

Net Assets, End of Period (Millions) $14,927 $12,443 $13,359 $10,554 $8,621Ratio of Total Expenses to Average Net Assets 0.05% 0.06% 0.06% 0.06% 0.07%Ratio of Net Investment Income to Average NetAssets

1.40% 1.51% 1.39% 1.63% 1.35%

Portfolio Turnover Rate2 13% 10% 11% 12% 6%

1 Calculated based on average shares outstanding.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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Vanguard Extended Market Index Fund Institutional Plus Shares

Year Ended December 31,For a Share Outstanding Throughout Each Period 2019 2018 2017 2016 2015Net Asset Value, Beginning of Period $186.80 $209.16 $179.47 $156.89 $164.36

Investment Operations

Net Investment Income 3.0781 3.2081 2.6111 2.525 2.254Net Realized and Unrealized Gain (Loss) onInvestments

49.178 (22.426) 29.741 22.668 (7.549)

Total from Investment Operations 52.256 (19.218) 32.352 25.193 (5.295)Distributions

Dividends from Net Investment Income (3.116) (3.142) (2.662) (2.613) (2.175)Distributions from Realized Capital Gains — — — — —Total Distributions (3.116) (3.142) (2.662) (2.613) (2.175)Net Asset Value, End of Period $235.94 $186.80 $209.16 $179.47 $156.89

Total Return 28.07% –9.35% 18.13% 16.18% –3.23%

Ratios/Supplemental Data

Net Assets, End of Period (Millions) $9,486 $7,559 $10,565 $13,530 $14,526Ratio of Total Expenses to Average Net Assets 0.04% 0.05% 0.05% 0.05% 0.05%Ratio of Net Investment Income to Average NetAssets

1.41% 1.52% 1.40% 1.64% 1.37%

Portfolio Turnover Rate2 13% 10% 11% 12% 6%

1 Calculated based on average shares outstanding.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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Vanguard Mid-Cap Index Fund Institutional Plus Shares

Year Ended December 31,For a Share Outstanding Throughout Each Period 2019 2018 2017 2016 2015Net Asset Value, Beginning of Period $186.34 $208.69 $177.51 $162.03 $166.65

Investment Operations

Net Investment Income 3.5981 3.4641 2.8561 2.564 2.461Net Realized and Unrealized Gain (Loss) onInvestments

54.052 (22.388) 31.179 15.524 (4.657)

Total from Investment Operations 57.650 (18.924) 34.035 18.088 (2.196)Distributions

Dividends from Net Investment Income (3.590) (3.426) (2.855) (2.608) (2.424)Distributions from Realized Capital Gains — — — — —Total Distributions (3.590) (3.426) (2.855) (2.608) (2.424)Net Asset Value, End of Period $240.40 $186.34 $208.69 $177.51 $162.03

Total Return 31.06% –9.21% 19.28% 11.24% –1.30%

Ratios/Supplemental Data

Net Assets, End of Period (Millions) $13,612 $11,426 $12,749 $11,415 $11,260Ratio of Total Expenses to Average Net Assets 0.03% 0.03% 0.03% 0.04% 0.05%Ratio of Net Investment Income to Average NetAssets

1.62% 1.63% 1.48% 1.56% 1.50%

Portfolio Turnover Rate2 15% 16% 14% 15% 15%

1 Calculated based on average shares outstanding.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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Vanguard Mid-Cap Index Fund Institutional Shares

Year Ended December 31,For a Share Outstanding Throughout Each Period 2019 2018 2017 2016 2015Net Asset Value, Beginning of Period $37.78 $42.32 $35.99 $32.85 $33.79

Investment Operations

Net Investment Income 0.7271 0.6971 0.5801 0.516 0.492Net Realized and Unrealized Gain (Loss) onInvestments

10.957 (4.547) 6.325 3.148 (0.947)

Total from Investment Operations 11.684 (3.850) 6.905 3.664 (0.455)Distributions

Dividends from Net Investment Income (0.724) (0.690) (0.575) (0.524) (0.485)Distributions from Realized Capital Gains — — — — —Total Distributions (0.724) (0.690) (0.575) (0.524) (0.485)Net Asset Value, End of Period $48.74 $37.78 $42.32 $35.99 $32.85

Total Return 31.04% –9.24% 19.29% 11.23% –1.33%

Ratios/Supplemental Data

Net Assets, End of Period (Millions) $20,425 $16,524 $18,222 $14,540 $12,278Ratio of Total Expenses to Average Net Assets 0.04% 0.04% 0.04% 0.05% 0.07%Ratio of Net Investment Income to Average NetAssets

1.62% 1.62% 1.47% 1.55% 1.48%

Portfolio Turnover Rate2 15% 16% 14% 15% 15%

1 Calculated based on average shares outstanding.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 withVanguard. Vanguard fund shares can be held directly with Vanguard or indirectlythrough an intermediary, such as a bank, a broker, or an investment advisor. Ifyou hold Vanguard fund shares directly with Vanguard, you should carefully readeach topic within this section that pertains to your relationship with Vanguard. Ifyou hold Vanguard fund shares indirectly through an intermediary (includingshares held in a brokerage account through Vanguard Brokerage Services®),please see Investing With Vanguard Through Other Firms, and also refer to youraccount agreement with the intermediary for information about transacting inthat account. If you hold Vanguard fund shares through an employer-sponsoredretirement or savings plan, please see Employer-Sponsored Plans. Vanguardreserves the right to change the following policies without notice. Please call orcheck online for current information. See Contacting Vanguard.

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

Purchasing Shares

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

Investment minimums may differ for certain categories of investors.

Account Minimums for Institutional Shares and InstitutionalPlus SharesTo open and maintain an account. Institutional Shares—$5 million; InstitutionalPlus Shares—$100 million. If you request Institutional Shares or Institutional PlusShares when you open a new account but the investment amount does notmeet the account minimum for the requested share class, your investment willbe placed in another share class of the Fund, as appropriate.

Certain Vanguard institutional clients may meet the minimum investmentamount by aggregating separate accounts within the same fund. Thisaggregation policy does not apply to financial intermediaries.

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Vanguard may charge additional recordkeeping fees for institutional clientswhose accounts are recordkept by Vanguard. Please contact your Vanguardrepresentative to determine whether additional recordkeeping fees apply toyour account.

To add to an existing account. Generally $1.

How to Initiate a Purchase RequestBe sure to check Exchanging Shares, Frequent-Trading Limitations, and OtherRules 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 areregistered for online access.

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

By mail. You may send Vanguard your account registration form and check toopen a new fund account. To add to an existing fund account, you may send yourcheck with an Invest-by-Mail form (from a transaction confirmation or youraccount statement) or with a deposit slip (available online).

How to Pay for a PurchaseBy electronic bank transfer. You may purchase shares of a Vanguard fundthrough an electronic transfer of money from a bank account. To establish theelectronic bank transfer service on an account, you must designate the bankaccount online, complete a form, or fill out the appropriate section of youraccount registration form. After the service is set up on your account, you canpurchase shares by electronic bank transfer on a regular schedule (AutomaticInvestment 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 callVanguard for instructions and policies on purchasing shares by wire. SeeContacting Vanguard.

By check. You may make initial or additional purchases to your fund account bysending a check with a deposit slip or by utilizing our mobile application if you areregistered for online access. Also see How to Initiate a Purchase Request. Make

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your check payable to Vanguard and include the appropriate fund number (e.g.,Vanguard—xx). For a list of Fund numbers (for Funds and share classes in thisprospectus), see Additional Information.

By exchange. You may purchase shares of a Vanguard fund using the proceedsfrom the simultaneous redemption of shares of another Vanguard fund. You mayinitiate an exchange online (if you are registered for online access), by telephone,or by mail with an exchange form. See Exchanging Shares.

Trade DateThe trade date for any purchase request received in good order will depend onthe day and time Vanguard receives your request, the manner in which you arepaying, and the type of fund you are purchasing. Your purchase will be executedusing the NAV as calculated on the trade date. NAVs are calculated only on daysthat the NYSE is open for trading (a business day). In the rare event the NYSEexperiences unanticipated disruptions and is unavailable at the close of thetrading day, NAVs will be calculated as of the close of regular trading on theNasdaq (or another alternate exchange if the Nasdaq is unavailable, asdetermined at Vanguard’s discretion), generally 4 p.m., Eastern time. The timeselected for NAV calculation in this rare event shall also serve as the conclusionof the trade date. See Share Price.

For purchases by check into all funds other than money market funds and forpurchases by exchange, wire, or electronic bank transfer into all funds: If thepurchase request is received by Vanguard on a business day before the close ofregular trading on the NYSE (generally 4 p.m., Eastern time), the trade date forthe purchase will be the same day. If the purchase request is received on abusiness day after the close of regular trading on the NYSE, or on a nonbusinessday, the trade date for the purchase will be the next business day.

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

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

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

Other Purchase Rules You Should KnowCheck purchases. All purchase checks must be written in U.S. dollars, be drawnon a U.S. bank, and be accompanied by good order instructions. Vanguard doesnot accept cash, traveler’s checks, starter checks, or money orders. In addition,Vanguard may refuse checks that are not made payable to Vanguard.

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

Refused or rejected purchase requests. Vanguard reserves the right to stopselling fund shares or to reject any purchase request at any time and withoutnotice, including, but not limited to, purchases requested by exchange fromanother Vanguard fund. This also includes the right to reject any purchaserequest because the investor has a history of frequent trading or because thepurchase may negatively affect a fund’s operation or performance.

Large purchases. Call Vanguard before attempting to invest a largedollar amount.

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

Converting Shares

When a conversion occurs, you receive shares of one class in place of shares ofanother 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 wereconverted. In other words, the conversion has no effect on the value of yourinvestment in the fund at the time of the conversion. However, the number ofshares you own after the conversion may be greater than or less than thenumber of shares you owned before the conversion, depending on the NAVs ofthe two share classes.

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

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

Trade DateThe trade date for any conversion request received in good order will depend onthe day and time Vanguard receives your request. Your conversion will beexecuted using the NAVs of the different share classes on the trade date. NAVsare calculated only on days that the NYSE is open for trading (a business day). Inthe rare event the NYSE experiences unanticipated disruptions and is unavailableat the close of the trading day, NAVs will be calculated as of the close of regulartrading on the Nasdaq (or another alternate exchange if the Nasdaq isunavailable, as determined at Vanguard’s discretion), generally 4 p.m., Easterntime. The time selected for NAV calculation in this rare event shall also serve asthe conclusion of the trade date. See Share Price.

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 onthe 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 regulartrading on the NYSE, or on a nonbusiness day, the trade date will be the nextbusiness day. See Other Rules You Should Know.

Conversions to Institutional Shares or Institutional Plus SharesYou are eligible for a self-directed conversion from another share class toInstitutional Shares or Institutional Plus Shares of the Fund, provided that youraccount meets all eligibility requirements. You may request a conversion throughour website (if you are registered for online access), or you may contactVanguard by telephone or by mail to request this transaction. Accounts thatqualify for Institutional Shares or Institutional Plus Shares will not beautomatically converted.

Conversions to Institutional Select SharesYou are eligible for a self-directed conversion from another share class toInstitutional Select Shares of the same Fund (if available), provided that youraccount meets all eligibility requirements. You may request a conversion throughour website (if you are registered for online access), through a trading platform,by mail, or by telephone. Accounts that qualify for Institutional Select Shares willnot be automatically converted.

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Conversions to ETF SharesOwners of conventional shares (i.e., not exchange-traded shares) issued by aFund may convert those shares to ETF Shares of equivalent value of the samefund. Please note that investors who own conventional shares through a401(k) plan or other employer-sponsored retirement or benefit plan generally maynot convert those shares to ETF Shares and should check with their plan sponsoror recordkeeper. ETF Shares, whether acquired through a conversion orpurchased on the secondary market, cannot be converted to conventional sharesby a shareholder. Also, ETF Shares of one fund cannot be exchanged for ETFShares of another fund.

ETF Shares must be held in a brokerage account. Thus, before convertingconventional shares to ETF Shares, you must have an existing, or open a new,brokerage account. This account may be with Vanguard Brokerage Services orwith any other brokerage firm.

Vanguard Brokerage Services does not impose a fee on conversions fromconventional shares to Vanguard ETF Shares. However, other brokerage firmsmay charge a fee to process a conversion. Vanguard reserves the right, in thefuture, to impose a transaction fee on conversions or to limit, temporarilysuspend, or terminate the conversion privilege. For additional information onconverting conventional shares to ETF Shares, please contact Vanguard to obtaina prospectus for ETF Shares. See Contacting Vanguard.

Mandatory Conversions to Another Share ClassIf an account no longer meets the balance requirements for a share class,Vanguard may automatically convert the shares in the account to another shareclass. A decline in the account balance because of market movement may resultin such a conversion. Vanguard will notify the investor in writing before anymandatory conversion occurs.

Redeeming Shares

How to Initiate a Redemption RequestBe sure to check Exchanging Shares, Frequent-Trading Limitations, and OtherRules You Should Know before placing your redemption request.

Online. You may request a redemption of shares or request an exchange throughour 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 anexchange. See Contacting Vanguard.

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By mail. You may send a form (available online) to Vanguard to redeem from afund account or to make an exchange.

How to Receive Redemption ProceedsBy electronic bank transfer. You may have the proceeds of a fund redemptionsent directly to a designated bank account. To establish the electronic banktransfer service on an account, you must designate a bank account online,complete a form, or fill out the appropriate section of your account registrationform. After the service is set up on your account, you can redeem shares byelectronic bank transfer on a regular schedule (Automatic Withdrawal Plan) orupon request. Your redemption request can be initiated online (if you areregistered for online access), by telephone, or by mail.

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

Please note that Vanguard charges a $10 wire fee for outgoing wireredemptions. The fee is assessed in addition to, rather than being withheld from,redemption proceeds and is paid directly to the fund in which you invest. Forexample, if you redeem $100 via a wire, you will receive the full $100, and the$10 fee will be assessed to your fund account through an additional redemptionof fund shares. If you redeem your entire fund account, your redemptionproceeds will be reduced by the amount of the fee. The wire fee does not applyto accounts held by Flagship and Flagship Select clients; accounts held throughintermediaries, including Vanguard Brokerage Services; or accounts held byinstitutional clients.

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

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

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Trade DateThe trade date for any redemption request received in good order will depend onthe day and time Vanguard receives your request and the manner in which youare redeeming. Your redemption will be executed using the NAV as calculated onthe trade date. NAVs are calculated only on days that the NYSE is open fortrading (a business day). In the rare event the NYSE experiences unanticipateddisruptions and is unavailable at the close of the trading day, NAVs will becalculated as of the close of regular trading on the Nasdaq (or another alternateexchange if the Nasdaq is unavailable, as determined at Vanguard’s discretion),generally 4 p.m., Eastern time. The time selected for NAV calculation in this rareevent shall also serve as the conclusion of the trade date. See Share Price.

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

• Note on timing of wire redemptions from money market funds: Fortelephone requests received by Vanguard on a business day before10:45 a.m., Eastern time (2 p.m., Eastern time, for Vanguard Prime MoneyMarket Fund; 12:30 p.m., Eastern time, for Vanguard Federal Money MarketFund), the redemption proceeds generally will leave Vanguard by the close ofbusiness the same day. For telephone requests received by Vanguard on abusiness day after those cut-off times, or on a nonbusiness day, and for allrequests other than by telephone, the redemption proceeds generally willleave Vanguard by the close of business on the next business day.

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

For redemptions by electronic bank transfer: If the redemption request isreceived by Vanguard on a business day before the close of regular trading onthe NYSE (generally 4 p.m., Eastern time), the trade date will be the same day. Ifthe redemption request is received on a business day after the close of regulartrading on the NYSE, or on a nonbusiness day, the trade date will be the nextbusiness day.

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

If your redemption request is received in good order, we typically expect thatredemption proceeds will be paid by a Fund within one business day of the tradedate; however, in certain circumstances, investors may experience a longersettlement 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 atvanguard.com or see Contacting Vanguard.

Other Redemption Rules You Should KnowDocumentation for certain accounts. Special documentation may be requiredto redeem from certain types of accounts, such as trust, corporate, nonprofit, orretirement accounts. Please call us before attempting to redeem from thesetypes of accounts.

Potentially disruptive redemptions. Vanguard reserves the right to pay all orpart of a redemption in kind—that is, in the form of securities—if we reasonablybelieve that a cash redemption would negatively affect the fund’s operation orperformance or that the shareholder may be engaged in market-timing orfrequent trading. Under these circumstances, Vanguard also reserves the right todelay payment of the redemption proceeds for up to seven calendar days. Bycalling us before you attempt to redeem a large dollar amount, you may avoidin-kind or delayed payment of your redemption. Please see Frequent-TradingLimitations 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 foryour purchase. This may take up to seven calendar days for shares purchased bycheck or by electronic bank transfer. If you have written a check on a fund withcheckwriting privileges, that check may be rejected if your fund account does nothave a sufficient available balance.

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Share certificates. Share certificates are no longer issued for Vanguard funds.Shares currently held in certificates cannot be redeemed, exchanged, converted,or transferred (reregistered) until you return the certificates (unsigned) toVanguard by registered mail.

Address change. If you change your address online or by telephone, there maybe up to a 14-day restriction (starting on the business day after your address ischanged) on your ability to request check redemptions online and by telephone.You can request a redemption in writing (using a form available online) at anytime. Confirmations of address changes are sent to both the old andnew addresses.

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

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

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

Exchanging Shares

An exchange occurs when you use the proceeds from the redemption of shares ofone Vanguard fund to simultaneously purchase shares of a different Vanguardfund.You can make exchange requests online (if you are registered for onlineaccess), 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 abusiness day) at the time an exchange request is received in good order, thetrade date generally will be the same day. See Other Rules You ShouldKnow—Good Order for additional information on all transaction requests.

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

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

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

Frequent-Trading Limitations

Because excessive transactions can disrupt management of a fund and increasethe fund’s costs for all shareholders, the board of trustees of each Vanguard fundplaces certain limits on frequent trading in the funds. Each Vanguard fund (otherthan money market funds and short-term bond funds, but including VanguardShort-Term Inflation-Protected Securities Index Fund) limits an investor’spurchases or exchanges into a fund account for 30 calendar days after theinvestor has redeemed or exchanged out of that fund account. ETF Shares arenot subject to these frequent-trading limits.

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

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, AutomaticExchange Service, Direct Deposit Service, Automatic Withdrawal Plan, RequiredMinimum Distribution Service, and Vanguard Small Business Online®.

• Discretionary transactions through Vanguard Personal Advisor Services®,Vanguard Institutional Advisory Services®, and Vanguard Digital Advisor™.

• Redemptions of shares to pay fund or account fees.

• Redemptions of shares to remove excess shareholder contributions to certaintypes of retirement accounts (including, but not limited to, IRAs and VanguardIndividual 401(k) Plans).

• 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.

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

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

• Purchases of shares with participant payroll or employer contributions orloan 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 ofthe 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.

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

* The following Vanguard fund accounts are subject to the frequent-tradinglimitations: SEP-IRAs, SIMPLE IRAs, certain Individual 403(b)(7) CustodialAccounts, 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 takeappropriate action, which may include applying to a client’s accounts the 30-daypolicy previously described, prohibiting a client’s purchases of fund shares,and/or revoking the client’s exchange privilege.

Accounts Held by IntermediariesWhen intermediaries establish accounts in Vanguard funds for the benefit oftheir clients, we cannot always monitor the trading activity of the individualclients. However, we review trading activity at the intermediary (omnibus) level,and if we detect suspicious activity, we will investigate and take appropriateaction. If necessary, Vanguard may prohibit additional purchases of fund shares

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by an intermediary, including for the benefit of certain of the intermediary’sclients. Intermediaries also may monitor their clients’ trading activities withrespect 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 remitthese fees to the funds. The application of purchase and redemption fees andfrequent-trading limitations may vary among intermediaries. There are noassurances that Vanguard will successfully identify all intermediaries or thatintermediaries will properly assess purchase and redemption fees or administerfrequent-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 thatmay apply.

Other Rules You Should Know

Prospectus and Shareholder Report MailingsWhen two or more shareholders have the same last name and address, just onesummary prospectus (or prospectus) and/or shareholder report may be sent inan attempt to eliminate the unnecessary expense of duplicate mailings. You mayrequest individual prospectuses and reports by contacting our Client ServicesDepartment by telephone or online. See Contacting Vanguard.

Vanguard.comRegistration. If you are a registered user of vanguard.com, you can review youraccount holdings; buy, sell, or exchange shares of most Vanguard funds; andperform most other transactions through our website. You must register for thisservice online.

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

Telephone TransactionsAutomatic. When we set up your account, we will automatically enable you todo business with us by telephone, unless you instruct us otherwise in writing.

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

Proof of a caller’s authority. We reserve the right to refuse a telephone requestif the caller is unable to provide the requested information or if we reasonablybelieve 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 thefollowing information:

• Authorization to act on the account (as the account owner or by legaldocumentation 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 OrderWe reserve the right to reject any transaction instructions that are not in “goodorder.” Good order generally means that your instructions:

• Are provided by the person(s) authorized in accordance with Vanguard’spolicies and procedures to access the account and request transactions.

• Include the fund name and account number.

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

Written instructions also must generally be provided on a Vanguard formand include:

• Signature(s) and date from the authorized person(s).*

• Signature guarantees or notarized signatures, if required for the type oftransaction. (Call Vanguard for specific requirements.)

• Any supporting documentation that may be required.*

Good order requirements may vary among types of accounts and transactions.For more information, consult our website at vanguard.com or seeContacting Vanguard.

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

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Future Trade-Date RequestsVanguard does not accept requests to hold a purchase, conversion, redemption,or exchange transaction for a future date. All such requests will receive tradedates as previously described in Purchasing Shares, Converting Shares,Redeeming Shares, and Exchanging Shares. Vanguard reserves the right toreturn future-dated purchase checks.

Accounts With More Than One OwnerIf an account has more than one owner or authorized person, Vanguard generallywill accept instructions from any one owner or authorized person.

Responsibility for FraudYou should take precautions to protect yourself from fraud. Keep youraccount-related information private, and review any account confirmations,statements, or other information that we provide to you as soon as you receivethem. Let us know immediately if you discover unauthorized activity or seesomething on your account that you do not understand or that looks unusual.

Vanguard will not be responsible for losses that result from transactions by aperson who we reasonably believe is authorized to act on your account.

Uncashed ChecksPlease cash your distribution or redemption checks promptly. Vanguard will notpay interest on uncashed checks. Vanguard may be required to transfer assetsrelated to uncashed checks to a state under the state’s abandoned property law.

Dormant AccountsIf your account has no activity in it for a period of time, Vanguard may berequired to transfer it to a state under the state’s abandoned property law,subject to potential federal or state withholding taxes.

Unusual CircumstancesIf you experience difficulty contacting Vanguard online or by telephone, you cansend us your transaction request on a Vanguard form by regular or express mail.

Investing With Vanguard Through Other FirmsYou may purchase or sell shares of most Vanguard funds through a financialintermediary, such as a bank, a broker, or an investment advisor. Please consultyour financial intermediary to determine which, if any, shares are availablethrough that firm and to learn about other rules that may apply. Your financialintermediary can provide you with account information and any required taxforms. Your financial intermediary will be responsible for taking reasonable

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actions to assist the retail or institutional money market fund to impose, lift, ormodify liquidity fees or redemption gates. You may be required to pay acommission on purchases of mutual fund shares made through afinancial intermediary.

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

Low-Balance AccountsEach Fund reserves the right to convert an investor’s Institutional Shares orInstitutional Plus Shares to another share class, as appropriate, if the investor’sfund account balance falls below the account minimum for any reason, includingmarket fluctuation. Any such conversion will be preceded by written notice tothe investor.

Right to Change PoliciesIn addition to the rights expressly stated elsewhere in this prospectus, Vanguardreserves the right, without notice, to (1) alter, add, or discontinue any conditionsof purchase (including eligibility requirements), redemption, exchange,conversion, service, or privilege at any time and (2) alter, impose, discontinue, orwaive any purchase fee, redemption fee, account service fee, or other feecharged to a shareholder or a group of shareholders. Changes may affect any orall investors. These actions will be taken when, at the sole discretion of Vanguardmanagement, Vanguard believes they are in the best interest of a fund.

Account RestrictionsVanguard reserves the right to: (1) redeem all or a portion of a fund/account tomeet a legal obligation, including tax withholding, tax lien, garnishment order, orother obligation imposed on your account by a court or government agency; (2)redeem shares, close an account, or suspend account privileges, features, oroptions in the case of threatening conduct or activity; (3) redeem shares, closean account, or suspend account privileges, features, or options if Vanguardbelieves or suspects that not doing so could result in a suspicious, fraudulent, orillegal transaction; (4) place restrictions on the ability to redeem any or all sharesin an account if it is required to do so by a court or government agency; (5) placerestrictions on the ability to redeem any or all shares in an account if Vanguardbelieves that doing so will prevent fraud, financial exploitation or abuse, or toprotect vulnerable investors; (6) freeze any account and/or suspend accountservices if Vanguard has received reasonable notice of a dispute regarding the

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assets in an account, including notice of a dispute between the registered orbeneficial account owners; and (7) freeze any account and/or suspend accountservices upon initial notification to Vanguard of the death of an account owner.

Share ClassesVanguard reserves the right, without notice, to change the eligibilityrequirements of its share classes, including the types of clients who are eligibleto purchase each share class.

Fund and Account Updates

Confirmation StatementsWe will send (or provide through our website, whichever you prefer) aconfirmation of your trade date and the amount of your transaction when youbuy, sell, exchange, or convert shares. However, we will not send confirmationsreflecting only checkwriting redemptions or the reinvestment of dividend orcapital gains distributions. For any month in which you had a checkwritingredemption, a Checkwriting Activity Statement will be sent to you itemizing thecheckwriting redemptions for that month. Promptly review each confirmationstatement that we provide to you. It is important that you contact Vanguardimmediately with any questions you may have about any transaction reflected ona confirmation statement, or Vanguard will consider the transactionproperly processed.

Portfolio SummariesWe will send (or provide through our website, whichever you prefer) quarterlyportfolio summaries to help you keep track of your accounts throughout the year.Each summary shows the market value of your account at the close of thestatement period, as well as all distributions, purchases, redemptions,exchanges, transfers, and conversions for the current calendar quarter (ormonth). Promptly review each summary that we provide to you. It is importantthat you contact Vanguard immediately with any questions you may have aboutany transaction reflected on the summary, or Vanguard will consider thetransaction properly processed.

Tax Information StatementsFor most accounts, Vanguard (or your intermediary) is required to provide annualtax forms to assist you in preparing your income tax returns. These forms aregenerally available for each calendar year early in the following year. Registeredusers of vanguard.com can also view certain forms through our website.

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Vanguard (or your intermediary) may also provide you with additional tax-relateddocumentation. For more information, consult our website at vanguard.com orsee Contacting Vanguard.

Annual and Semiannual ReportsWe will send (or provide through our website, whichever you prefer) reportsabout Vanguard U.S. Stock Index Mid-Capitalization Fund twice a year, inFebruary and August. These reports include overviews of the financial marketsand provide the following specific Fund information:

• Performance assessments and comparisons with industry benchmarks.

• Reports from the advisor.

• Financial statements with listings of Fund holdings.

Portfolio HoldingsPlease consult the Funds’ Statement of Additional Information or our website fora description of the policies and procedures that govern disclosure of a Fund’sportfolio holdings.

Employer-Sponsored Plans

Your plan administrator or your employee benefits office can provide you withdetailed information on how to participate in your plan and how to elect a Fundas an investment option.

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

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

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

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

TransactionsProcessing times for your transaction requests may differ among recordkeepersor among transaction and funding types. Your plan’s recordkeeper (which mayalso be Vanguard) will determine the necessary processing time frames for yourtransaction requests prior to submission to a Fund. Consult your recordkeeper orplan administrator for more information.

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

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Contacting Vanguard

WebVanguard.com For the most complete source of Vanguard news

For fund, account, and service informationFor most account transactionsFor literature requests24 hours a day, 7 days a week

PhoneVanguard Tele-Account®

800-662-6273For automated fund and account informationToll-free, 24 hours a day, 7 days a week

Investor Information 800-662-7447(Text telephone for people withhearing impairment at 800-749-7273)

For fund and service informationFor literature requests

Client Services 800-662-2739(Text telephone for people withhearing impairment at 800-749-7273)

For account informationFor most account transactions

Participant Services 800-523-1188(Text telephone for people withhearing impairment at 800-749-7273)

For information and services for participants inemployer-sponsored plans

Institutional Division888-809-8102

For information and services for large institutionalinvestors

Financial Advisor and IntermediarySales Support 800-997-2798

For information and services for financial intermediariesincluding financial advisors, broker-dealers, trustinstitutions, and insurance companies

Financial Advisory and IntermediaryTrading Support 800-669-0498

For account information and trading support forfinancial intermediaries including financial advisors,broker-dealers, trust institutions, and insurancecompanies

Additional Information

InceptionDate

NewspaperAbbreviation

VanguardFund Number

CUSIPNumber

Extended Market Index Fund

Institutional Shares 7/7/1997 ExtndInst 856 922908884Institutional Plus Shares 1/14/2011 ExtndIstPl 1860 922908371Mid-Cap Index Fund

Institutional Shares 5/21/1998 MidCpInst 864 922908835Institutional Plus Shares 12/15/2010 MidCpIstPl 1859 922908389

CGS identifiers have been provided by CUSIP Global Services, managed on behalf of the American BankersAssociation by Standard & Poor’s Financial Services, LLC, and are not for use or dissemination in a manner that wouldserve as a substitute for any CUSIP service. The CUSIP Database, ©2020 American Bankers Association. “CUSIP” is aregistered trademark of the American Bankers Association.

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CFA® is a registered trademark owned by CFA Institute.

Vanguard funds are not sponsored, endorsed, sold, or promoted by the University of Chicago or its Center forResearch in Security Prices, and neither the University of Chicago nor its Center for Research in Security Prices makesany representation regarding the advisability of investing in the funds.

The “Standard & Poor’s Completion Index” (the “Index”) is a product of S&P Dow Jones Indices LLC (“SPDJI”), andhas been licensed for use by Vanguard. Standard & Poor’s® and S&P® are registered trademarks of Standard & Poor’sFinancial Services LLC (“S&P”); Dow Jones® is a registered trademark of Dow Jones Trademark Holdings LLC (“DowJones”); S&P® and S&P 500® are trademarks of S&P; and these trademarks have been licensed for use by SPDJI andsublicensed for certain purposes by Vanguard. Vanguard Extended Market Index Fund is not sponsored, endorsed, soldor promoted by SPDJI, Dow Jones, S&P, or any of their respective affiliates (collectively, “S&P Dow Jones Indices”).S&P Dow Jones Indices makes no representation or warranty, express or implied, to the owners of VanguardExtended Market Index Fund or any member of the public regarding the advisability of investing in securities generallyor in Vanguard Extended Market Index Fund particularly or the ability of the Standard & Poor’s Completion Index totrack general market performance. S&P Dow Jones Indices’ only relationship to Vanguard with respect to theStandard & Poor’s Completion Index is the licensing of the Index and certain trademarks, service marks and/or tradenames of S&P Dow Jones Indices and/or its licensors. The Standard & Poor’s Completion Index is determined,composed and calculated by S&P Dow Jones Indices without regard to Vanguard or Vanguard Extended Market IndexFund. S&P Dow Jones Indices has no obligation to take the needs of Vanguard or the owners of Vanguard ExtendedMarket Index Fund into consideration in determining, composing or calculating the Standard & Poor’s CompletionIndex. S&P Dow Jones Indices is not responsible for and has not participated in the determination of the prices, andamount of Vanguard Extended Market Index Fund or the timing of the issuance or sale of Vanguard Extended MarketIndex Fund or in the determination or calculation of the equation by which Vanguard Extended Market Index Fund is tobe converted into cash, surrendered or redeemed, as the case may be. S&P Dow Jones Indices has no obligation orliability in connection with the administration, marketing or trading of Vanguard Extended Market Index Fund. There isno assurance that investment products based on the Standard & Poor’s Completion Index will accurately track indexperformance or provide positive investment returns. S&P Dow Jones Indices LLC is not an investment advisor.Inclusion of a security within an index is not a recommendation by S&P Dow Jones Indices to buy, sell, or hold suchsecurity, nor is it considered to be investment advice.

S&P DOW JONES INDICES DOES NOT GUARANTEE THE ADEQUACY, ACCURACY, TIMELINESS AND/OR THECOMPLETENESS OF THE INDEX OR ANY DATA RELATED THERETO OR ANY COMMUNICATION, INCLUDING BUT NOTLIMITED TO, ORAL OR WRITTEN COMMUNICATION (INCLUDING ELECTRONIC COMMUNICATIONS) WITH RESPECTTHERETO. S&P DOW JONES INDICES SHALL NOT BE SUBJECT TO ANY DAMAGES OR LIABILITY FOR ANY ERRORS,OMISSIONS, OR DELAYS THEREIN. S&P DOW JONES INDICES MAKES NO EXPRESS OR IMPLIED WARRANTIES,AND EXPRESSLY DISCLAIMS ALL WARRANTIES, OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSEOR USE OR AS TO RESULTS TO BE OBTAINED BY VANGUARD, OWNERS OF VANGUARD EXTENDED MARKET INDEXFUND, OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE INDICES OR WITH RESPECT TO ANY DATARELATED THERETO. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT WHATSOEVER SHALL S&P DOWJONES INDICES BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGESINCLUDING BUT NOT LIMITED TO, LOSS OF PROFITS, TRADING LOSSES, LOST TIME OR GOODWILL, EVEN IF THEYHAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, WHETHER IN CONTRACT, TORT, STRICT LIABILITY,OR OTHERWISE. THERE ARE NO THIRD PARTY BENEFICIARIES OF ANY AGREEMENTS OR ARRANGEMENTSBETWEEN S&P DOW JONES INDICES AND VANGUARD, OTHER THAN THE LICENSORS OF S&P DOWJONES INDICES.

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Glossary of Investment Terms

Capital Gains Distributions. Payments to mutual fund shareholders of gainsrealized on securities that a fund has sold at a profit, minus any realized losses.

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

Dividend Distributions. Payments to mutual fund shareholders of income frominterest or dividends generated by a fund’s investments.

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

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

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

Joint Committed Credit Facility. Each Fund participates, along with other fundsmanaged by Vanguard, in a committed credit facility provided by a syndicate oflenders pursuant to a credit agreement that may be renewed annually; eachVanguard fund is individually liable for its borrowings, if any, under the creditfacility. The amount and terms of the committed credit facility are subject toapproval by the Funds’ board of trustees and renegotiation with the lendersyndicate on an annual basis.

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

MSCI US Mid Cap 450 Index. An index that tracks the stocks of approximately450 mid-capitalization companies in the U.S. market.

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

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New York Stock Exchange (NYSE). A stock exchange based in New York Citythat is open for regular trading on business days, Monday through Friday, from9:30 a.m. to 4 p.m., Eastern time.

Price/Earnings (P/E) Ratio. The current share price of a stock, divided by itsper-share earnings (profits). A stock selling for $20, with earnings of $2 pershare, has a price/earnings ratio of 10.

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

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

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

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

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Connect with Vanguard®

> vanguard.com

For More InformationIf you would like more information about VanguardU.S. Stock Index Mid-Capitalization Fund, the followingdocuments are available free upon request:

Annual/Semiannual Reports to ShareholdersAdditional information about the Funds’ investments isavailable in the Funds’ annual and semiannual reportsto shareholders. In the annual report, you will find adiscussion of the market conditions and investmentstrategies that significantly affected the Funds’performance during their last fiscal year.

Statement of Additional Information (SAI)The SAI provides more detailed information about theFunds and is incorporated by reference into (and thuslegally a part of) this prospectus.

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

If you are an individual investor:Telephone: 800-662-7447;Text telephone for people with hearing impairment:800-749-7273

If you are a client of Vanguard’s Institutional Division:Telephone: 888-809-8102; Text telephone for peoplewith hearing impairment: 800-749-7273

If you are a current Vanguard shareholder and wouldlike information about your account, accounttransactions, and/or account statements, please call:

Client Services DepartmentTelephone: 800-662-2739;Text telephone for people with hearing impairment:800-749-7273

Information Provided by the Securities andExchange Commission (SEC)Reports and other information about the Funds areavailable in the EDGAR database on the SEC’s websiteat www.sec.gov, or you can receive copies of thisinformation, for a fee, by electronic request at thefollowing email address: [email protected].

Funds’ Investment Company Act file number: 811-02652

© 2020 The Vanguard Group, Inc. All rights reserved.Vanguard Marketing Corporation, Distributor.

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