Vanguard Balanced Index FundProspectus

April 28, 2020

Investor Shares & Admiral™ Shares

Vanguard Balanced Index Fund Investor Shares (VBINX)

Vanguard Balanced Index Fund Admiral Shares (VBIAX)

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 Fund 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.

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

Fund Summary 1

Investing in Index Funds 7

More on the Fund 8

The Fund and Vanguard 20

Investment Advisor 21

Dividends, Capital Gains, and Taxes 22

Share Price 25

Financial Highlights 27

Investing With Vanguard 29

Purchasing Shares 29

Converting Shares 32

Redeeming Shares 34

Exchanging Shares 37

Frequent-Trading Limitations 38

Other Rules You Should Know 40

Fund and Account Updates 44

Employer-Sponsored Plans 46

Contacting Vanguard 47

Additional Information 47

Glossary of Investment Terms 50

Fund Summary

Investment ObjectiveWith 60% of its assets, the Fund seeks to track the performance of a benchmarkindex that measures the investment return of the overall U.S. stock market. With40% of its assets, the Fund seeks to track the performance of a broad,market-weighted bond index.

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

Shareholder Fees(Fees paid directly from your investment)

Admiral Shares Investor SharesSales Charge (Load) Imposed on Purchases None NonePurchase Fee None NoneSales Charge (Load) Imposed on Reinvested Dividends None NoneRedemption Fee None NoneAccount Service Fee Per Year(for certain fund account balances below $10,000) $20 None

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

Admiral Shares Investor SharesManagement Fees 0.06% 0.17%12b-1 Distribution Fee None NoneOther Expenses 0.01% 0.01%Total Annual Fund Operating Expenses 0.07% 0.18%

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Examples

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

1 Year 3 Years 5 Years 10 YearsAdmiral Shares $7 $23 $40 $90Investor Shares $18 $58 $101 $230

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 37% of the average value of its portfolio.

Principal Investment StrategiesThe Fund employs an indexing investment approach designed to track theperformance of two benchmark indexes. The Fund invests by sampling its targetindexes, meaning that it holds a range of securities that, in the aggregate,approximates the full indexes in terms of key characteristics.

With approximately 60% of its assets, the Fund seeks to track the investmentperformance of the CRSP US Total Market Index, which representsapproximately 100% of the investable U.S. stock market and includes large-,mid-, small-, and micro-cap stocks regularly traded on the New York StockExchange and Nasdaq. The Fund samples the Index by holding a broadlydiversified collection of stocks that, in the aggregate, approximates thefull Index.

With approximately 40% of its assets, the Fund seeks to track the investmentperformance of the Bloomberg Barclays U.S. Aggregate Float Adjusted Index,which represents a wide spectrum of public, investment-grade, taxable, fixedincome securities in the United States—including government, corporate, and

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international dollar-denominated bonds, as well as mortgage-backed andasset-backed securities—all with maturities of more than 1 year. At least 80% ofthe bond portion of the Fund is invested in bonds held in the Bloomberg BarclaysU.S. Aggregate Float Adjusted Index, and all of the Fund’s bond holdings areselected through the sampling process. The bond portion of the Fund maintainsa dollar-weighted average maturity consistent with that of the Index. As ofDecember 31, 2019, the dollar-weighted average maturity of the Index was8.2 years.

Principal RisksThe Fund is subject to the risks associated with the stock and bond markets, anyof which could cause an investor to lose money, and the level of risk may varybased on market conditions. However, because stock and bond prices can movein different directions or to different degrees, the Fund’s bond holdings maycounteract some of the volatility experienced by the Fund’s stock holdings.

• With approximately 60% of its assets allocated to stocks, the Fund isproportionately subject to stock market risk, which is the chance that stockprices overall will decline. Stock markets tend to move in cycles, with periods ofrising prices and periods of falling prices. In addition, the Fund’s target stockindex may, at times, become focused in stocks of a particular market sector,which would subject the Fund to proportionately higher exposure to the risks ofthat sector.

• With approximately 40% of its assets allocated to bonds, the Fund isproportionately subject to bond risks, including interest rate risk, which is thechance that bond prices will decline because of rising interest rates; income risk,which is the chance that the Fund’s income will decline because of fallinginterest rates; credit risk, which is the chance that a bond issuer will fail to payinterest or principal in a timely manner or that negative perceptions of theissuer’s ability to make such payments will cause the price of that bond todecline; and call risk, which is the chance that during periods of falling interestrates, issuers of callable bonds may call (redeem) securities with higher couponrates or interest rates before their maturity dates. The Fund would then lose anyprice appreciation above the bond’s call price and would be forced to reinvest theunanticipated proceeds at lower interest rates, resulting in a decline in theFund’s income. Such redemptions and subsequent reinvestments would alsoincrease the Fund’s portfolio turnover rate.

• The Fund is also subject to index sampling risk, which is the chance that thesecurities selected for the Fund will not provide investment performancematching that of the Fund’s target indexes.

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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. Because the eligibility requirements for the Fund’sAdmiral Shares were recently changed, annual total returns for the Fund’sAdmiral Shares are relevant for most investors. Accordingly, the informationpresented in the bar chart reflects the performance of the Fund’s AdmiralShares. The bar chart shows how the performance of the Fund‘s Admiral Shareshas varied from one calendar year to another over the periods shown. The tableshows how the average annual total returns of the share classes presentedcompare with those of relevant market indexes and other comparative indexes,which have investment characteristics similar to those of the Fund. The SplicedTotal Stock Market Index reflects the performance of the MSCI US Broad MarketIndex through June 2, 2013, and the CRSP US Total Market Index thereafter. TheBalanced Composite Index is weighted 60% MSCI US Broad Market Index and40% Bloomberg Barclays U.S. Aggregate Float Adjusted Index throughJanuary 14, 2013, and 60% CRSP US Total Market Index and 40% BloombergBarclays U.S. Aggregate Float Adjusted Index thereafter. Keep in mind that theFund’s past performance (before and after taxes) does not indicate how the Fundwill perform in the future. Updated performance information is available on ourwebsite at vanguard.com/performance or by calling Vanguard toll-free at800-662-7447.

Annual Total Returns — Vanguard Balanced Index Fund Admiral Shares

2010 2011 2012 2013 2014 2015 2016 2017 2018 2019

0%5%

10%15%20%25%30%

-5%-10%

13.29

4.29

11.49

18.10

9.99

0.51

8.7713.89

–2.86

21.79

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

Total Return QuarterHighest 9.57% March 31, 2019Lowest -8.09% December 31, 2018

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Average Annual Total Returns for Periods Ended December 31, 2019

1 Year 5 Years 10 YearsVanguard Balanced Index Fund Admiral Shares

Return Before Taxes 21.79% 8.05% 9.68%Return After Taxes on Distributions 20.86 7.29 8.97Return After Taxes on Distributions and Sale of Fund Shares 13.11 6.05 7.67Vanguard Balanced Index Fund Investor Shares

Return Before Taxes 21.67% 7.93% 9.54%Comparative Indexes(reflect no deduction for fees, expenses, or taxes)MSCI US Broad Market Index 31.07% 11.26% 13.48%CRSP US Total Market Index 30.84 11.21 —Spliced Total Stock Market Index 30.84 11.21 13.44Bloomberg Barclays U.S. Aggregate Float Adjusted Index 8.87 3.07 3.78Balanced Composite Index 21.87 8.17 9.84

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 AdmiralShares 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

William A. Coleman, CFA, Portfolio Manager at Vanguard. He has co-managedthe stock portion of the Fund since 2016.

Gerard C. O’Reilly, Principal of Vanguard. He has co-managed the stock portion ofthe Fund since 2016.

Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard’sFixed Income Indexing Americas. He has managed the bond portion of the Fundsince 2013.

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 Admiral Shares is $3,000. The minimuminvestment amount required to add to an existing Fund account is generally $1.Investor Shares are generally available only to Vanguard funds that operate asfunds of funds and to certain retirement plan clients that receive recordkeepingservices from Vanguard. Financial intermediaries, institutional clients, andVanguard-advised clients should contact Vanguard for information on specialeligibility rules that may apply to them regarding Admiral Shares. If you areinvesting through an intermediary, please contact that firm directly for moreinformation regarding your eligibility. If you are investing through anemployer-sponsored retirement or savings plan, your plan administrator or yourbenefits office can provide you with detailed information on how you can investthrough 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, dealer markups, and othertransaction costs—to a minimum compared with actively managed funds.

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More on the Fund

This prospectus describes the principal risks you would face as a 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 the Fund is the rightinvestment for you. We suggest that you keep this prospectus forfuture reference.

Share Class OverviewThis prospectus offers the Fund’s Investor Shares and Admiral Shares. Aseparate prospectus offers the Fund’s Institutional Shares, which are generallyfor investors who invest a minimum of $5 million.

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

Plain Talk About Fund Expenses

All mutual funds have operating expenses. These expenses, which arededucted from a fund’s gross income, are expressed as a percentage of thenet assets of the fund. Assuming that operating expenses remain as statedin the Fees and Expenses section, Vanguard Balanced Index Fund’s expenseratios would be as follows: for Investor Shares, 0.18%, or $1.80 per $1,000of average net assets; for Admiral Shares, 0.07%, or $0.70 per $1,000 ofaverage net assets. The average expense ratio for mixed-asset targetallocation growth funds in 2019 was 0.80%, or $8.00 per $1,000 of averagenet assets (derived from data provided by Lipper, a Thomson ReutersCompany, which reports on the mutual fund industry).

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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 the Fund uses in pursuit of its objective. The Fund‘s board of trustees, whichoversees the Fund’s management, may change investment strategies or policiesin the interest of shareholders without a shareholder vote, unless thosestrategies or policies are designated as fundamental. Note that the Fund’sinvestment objective is not fundamental and may be changed without ashareholder vote.

Plain Talk About Balanced Funds

Balanced funds are generally investments that seek to provide somecombination of income and capital appreciation by investing in a mix ofstocks and bonds. Because prices of stocks and bonds can responddifferently to economic events and influences, a balanced fund shouldexperience less volatility than a fund investing exclusively in stocks.

Market Exposure

StocksApproximately 60% of the Fund’s assets are invested in stocks.

The 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. In addition, theFund’s target stock 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.

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Although the Fund will include a broadly diversified collection of stocks in theCRSP US Total Market Index, it will not include all of the securities in the Index.Instead, the Fund will invest in a representative sample of stocks.

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 marketcapitalization of the Fund’s stock holdings as of December 31, 2019, was$83 billion.

Historically, mid-, small-, and micro-cap stocks have been more volatilethan—and at times have performed quite differently from—large-cap stocks.

BondsApproximately 40% of the Fund’s assets are invested in bonds.

The Fund is subject to interest rate risk, which is the chance that bondprices will decline because of rising interest rates. Interest rate riskshould be moderate for the Fund because the Fund invests only a portionof its assets in bonds and because the average duration of the Fund’sbond portfolio is generally intermediate-term. The prices ofintermediate-term bonds are less sensitive to interest rate changes thanare the prices of long-term bonds.

Although bonds are often thought to be less risky than stocks, there have beenperiods when bond prices have fallen significantly because of rising interestrates. For instance, prices of long-term bonds fell by almost 48% betweenDecember 1976 and September 1981.

To illustrate the relationship between bond prices and interest rates, thefollowing table shows the effect of a 1% and a 2% change (both up and down) ininterest rates on the values of three noncallable bonds (i.e., bonds that cannotbe redeemed by the issuer) of different maturities, each with a face valueof $1,000.

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How Interest Rate Changes Affect the Value of a $1,000 Bond1

Type of Bond (Maturity)After a 1%

IncreaseAfter a 1%Decrease

After a 2%Increase

After a 2%Decrease

Short-Term (2.5 years) $977 $1,024 $954 $1,049

Intermediate-Term (10 years) 922 1,086 851 1,180

Long-Term (20 years) 874 1,150 769 1,328

1 Assuming a 4% coupon rate.

These figures are for illustration only; you should not regard them as anindication of future performance of the bond market as a whole or the Fund inparticular. Also, because bonds make up only a portion of the Fund’s assets,changes in interest rates may not have as dramatic an effect on the Fund as theywould on a fund made up entirely of bonds.

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Plain Talk About Bonds and Interest Rates

As a rule, when interest rates rise, bond prices fall. The opposite is also true:Bond prices go up when interest rates fall. Why do bond prices and interestrates move in opposite directions? Let’s assume that you hold a bondoffering a 4% yield. A year later, interest rates are on the rise and bonds ofcomparable quality and maturity are offered with a 5% yield. Withhigher-yielding bonds available, you would have trouble selling your 4% bondfor the price you paid—you would probably have to lower your asking price.On the other hand, if interest rates were falling and 3% bonds were beingoffered, you should be able to sell your 4% bond for more than you paid.

How mortgage-backed securities are different: In general, declining interestrates will not lift the prices of mortgage-backed securities—such as thoseguaranteed by the Government National Mortgage Association—as much asthe prices of comparable bonds. Why? Because when interest rates fall, thebond market tends to discount the prices of mortgage-backed securities forprepayment risk—the possibility that homeowners will refinance theirmortgages at lower rates and cause the bonds to be paid off prior tomaturity. In part to compensate for this prepayment possibility,mortgage-backed securities tend to offer higher yields than other bonds ofcomparable credit quality and maturity. In contrast, when interest rates rise,prepayments tend to slow down, subjecting mortgage-backed securities toextension risk—the possibility that homeowners will repay their mortgagesat slower rates. This will lengthen the duration or average life ofmortgage-backed securities held by a fund and delay the fund’s ability toreinvest proceeds at higher interest rates, making the fund more sensitive tochanges in interest rates.

Changes in interest rates can affect bond income as well as bond prices.

The Fund is subject to income risk, which is the chance that the Fund’sincome will decline because of falling interest rates. A fund holdingbonds will experience a decline in income when interest rates fallbecause the fund then must invest new cash flow and cash frommaturing bonds in lower-yielding bonds.

Although income risk for intermediate-term bonds—like those held by theFund—is considered moderate, this risk should be low for the Fund because itinvests only a portion of its assets in bonds.

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Plain Talk About Bond Maturities

A bond is issued with a specific maturity date—the date when the issuermust pay back the bond’s principal (face value). Bond maturities range fromless than 1 year to more than 30 years. Typically, the longer a bond’s maturity,the more price risk you, as a bond investor, will face as interest ratesrise—but also the higher the potential yield you could receive. Longer-termbonds are more suitable for investors willing to take a greater risk of pricefluctuations to get higher and more stable interest income. Shorter-termbond investors should be willing to accept lower yields and greater incomevariability in return for less fluctuation in the value of their investment. Thestated maturity of a bond may differ from the effective maturity of a bond,which takes into consideration that an action such as a call or refunding maycause bonds to be repaid before their stated maturity dates.

The Fund is subject to credit risk, which is the chance that a bond issuerwill fail to pay interest or principal in a timely manner or that negativeperceptions of the issuer’s ability to make such payments will cause theprice of that bond to decline.

Credit risk should be low for the Fund because it purchases only bonds that areof investment-grade quality.

Plain Talk About Credit Quality

A bond’s credit quality rating is an assessment of the issuer’s ability to payinterest on the bond and, ultimately, to repay the principal. The lower thecredit quality, the greater the perceived chance that the bond issuer willdefault, or fail to meet its payment obligations. All things being equal, thelower a bond’s credit quality, the higher its yield should be to compensateinvestors for assuming additional risk.

The Fund is subject to call risk, which is the chance that during periods offalling interest rates, issuers of callable bonds may call (redeem)securities with higher coupon rates or interest rates before their maturitydates. The Fund would then lose any price appreciation above the bond’scall price and would be forced to reinvest the unanticipated proceeds atlower interest rates, resulting in a decline in the Fund’s income. Suchredemptions and subsequent reinvestments would also increase theFund’s portfolio turnover rate.

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The Fund is also subject to prepayment risk, which is the chance that duringperiods of falling interest rates, homeowners will refinance their mortgagesbefore their maturity dates, resulting in prepayment of mortgage-backedsecurities held by the Fund. The Fund would then lose any price appreciationabove the mortgage’s principal and would be forced to reinvest the unanticipatedproceeds at lower interest rates, resulting in a decline in the Fund’s income.Such prepayments and subsequent reinvestments would also increase theFund’s portfolio turnover rate. Because the Fund invests only a portion of itsassets in callable bonds and mortgage-backed securities, call risk andprepayment risk for the Fund should be low.

The Fund is subject to extension risk. Extension risk is the chance that duringperiods of rising interest rates, certain debt securities will be paid offsubstantially more slowly than originally anticipated, and the value of thosesecurities may fall. For funds that invest in mortgage-backed securities,extension risk is the chance that during periods of rising interest rates,homeowners will repay their mortgages at slower rates. Extension risk shouldbe low for the Fund because it invests only a portion of its assets in bonds.

To a limited extent, the Fund is subject to event risk, which is the chance thatcorporate fixed income securities held by the Fund may suffer a substantialdecline in credit quality and market value because of a corporate restructuring oranother corporate event.

The Fund’s balanced portfolio, in the long run, should result in less investmentrisk—and a lower investment return—than a fund investing exclusively in stocks.

Market disruptions can adversely affect local and global markets as well asnormal market conditions and operations. Any such disruptions could have anadverse impact on the value of the Fund’s investments and Fund performance.

Security SelectionIndex sampling strategy. Because it would be very expensive and inefficient tobuy and sell all the securities held in its target indexes, the Fund uses an index“sampling” technique to select securities. Using computer programs, the Fundgenerally selects a representative sample of securities that approximates the fulltarget indexes in terms of key risk factors and other characteristics. In its stockportion, the Fund holds a broadly diversified collection of stocks thatapproximates the CRSP US Total Market Index in terms of factors such asindustry weightings, market capitalization, and other financial characteristics ofstocks. In its bond portion, the Fund considers factors such as duration, cashflow, quality, and callability of the underlying bonds when sampling the

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Bloomberg Barclays U.S. Aggregate Float Adjusted Index. In addition, the Fund’sbond portion keeps industry sector and subsector exposure within tightboundaries compared with that of the Index.

Because the Fund does not hold all the securities in its target indexes, some ofthe securities (and issuers) that are held will likely be overweighted (orunderweighted) compared with the target indexes.

The Fund is subject to index sampling risk, which is the chance that thesecurities selected for the Fund will not provide investment performancematching that of the Fund’s target indexes.

Types of bonds. The Fund’s target index for bonds, the Bloomberg BarclaysU.S. Aggregate Float Adjusted Index, represents a wide spectrum ofinvestment-grade fixed income securities in the United States—includinggovernment, corporate, and international dollar-denominated bonds, as well asmortgage-backed and asset-backed securities—all with maturities of more than1 year.

As of December 31, 2019, the Fund’s bond portion was made up of the followingtypes of bonds:

U.S.Government/Agency Corporate

Mortgage-Backed

InternationalDollar-Denominated Other Total

43.9% 28.9% 22.5% 4.0% 0.7% 100%

An explanation of each type of bond follows:

• U.S. government and agency bonds represent loans by investors to theU.S. Treasury or a wide variety of government agencies and instrumentalities.Timely payment of principal and interest on U.S. Treasury bonds is alwaysguaranteed by the full faith and credit of the U.S. government; many (but not all)agency bonds have the same guarantee. The market values of U.S. governmentand agency securities and U.S. Treasury securities are subject to fluctuation.

• Corporate bonds are IOUs issued by businesses that want to borrow moneyfor some purpose—often to develop a new product or service, to expand into anew market, or to buy another company. As with other types of bonds, theissuer promises to repay the principal on a specific date and to make interestpayments in the meantime. The amount of interest offered depends both onmarket conditions and on the financial health of the corporation issuing thebonds; a company whose credit rating is not strong will have to offer a higherinterest rate to obtain buyers for its bonds. Corporate bonds include securitiesthat are backed by a pool of underlying assets (asset-backed securities) or

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commercial mortgages (commercial mortgage-backed bonds). The Fund expectsto purchase only investment-grade corporate bonds.

• Mortgage-backed securities represent interests in underlying pools ofmortgages. Unlike ordinary bonds, which generally pay a fixed rate of interest atregular intervals and then repay principal upon maturity, mortgage-backedsecurities pass through both interest and principal from underlying mortgages aspart of their regular payments. Because the mortgages underlying the securitiescan be prepaid at any time by homeowners or corporate borrowers,mortgage-backed securities are subject to prepayment risk. These types ofsecurities are issued by a number of government agencies, including theGovernment National Mortgage Association (GNMA), the Federal Home LoanMortgage Corporation (FHLMC), and the Federal National Mortgage Association(FNMA). GNMAs are guaranteed by the full faith and credit of the U.S.government as to the timely payment of principal and interest; mortgage-backedsecurities issued by other government agencies or private corporations are not.

The Fund may also invest in conventional mortgage-backed securities—which arepackaged by private corporations and are not guaranteed by the U.S.government—and enter into mortgage-dollar-roll transactions. In amortgage-dollar-roll transaction, a fund sells mortgage-backed securities to adealer and simultaneously agrees to purchase similar securities in the future at apredetermined price. These transactions simulate an investment inmortgage-backed securities and have the potential to enhance a fund’s returnsand reduce its administrative burdens, compared with holding mortgage-backedsecurities directly. These transactions may increase a fund’s portfolio turnoverrate. Mortgage dollar rolls will be used only if consistent with the Fund’sinvestment objective and risk profile.

• International dollar-denominated bonds are bonds denominated in U.S. dollarsand issued by foreign governments and companies. To the extent that the Fundowns foreign bonds, it is subject to country risk, which is the chance that worldevents—such as political upheaval, financial troubles, or natural disasters—willadversely affect the value and/or liquidity of securities issued by companies inforeign countries. Because the bond’s value is designated in dollars rather thanin the currency of the issuer’s country, the investor is not exposed to currencyrisk; rather, the issuer assumes the risk, usually to attract U.S. investors.

Other Investment Policies and RisksThe Fund reserves the right to substitute a different index for either of theindexes that it currently tracks if a current index is discontinued, if the Fund’sagreement with the sponsor of a current index is terminated, or for any other

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reason determined in good faith by the Fund’s board of trustees. In any suchinstance, the substitute index would represent the same market segment as thecurrent index.

The Fund may invest in foreign stocks to the extent necessary to carry out itsinvestment strategy of holding a representative sample of the stocks that makeup the index it tracks. It is not expected that the Fund will invest more than 5%of its assets in foreign stocks.

Up to 20% of the bond portion of the Fund may be used to purchase nonpublic,investment-grade securities, generally referred to as 144A securities, as well assmaller public issues or medium-term notes not included in the BloombergBarclays U.S. Aggregate Float Adjusted Index because of the size of the issue.Subject to the same 20% limit, the Fund also may invest in relativelyconservative classes of collateralized mortgage obligations (CMOs), which offer ahigh degree of cash-flow predictability and a low level of vulnerability tomortgage prepayment risk. To reduce credit risk, these CMOs are purchasedonly if issued by agencies of the U.S. government or by private companies thatcarry high-quality investment-grade ratings. The vast majority of any suchsecurities will have characteristics and risks similar to those in the Index.

The Fund may invest, to a limited extent, in derivatives. 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 Fund to risks different from, and possibly greater than, those ofinvestments directly in the underlying securities or assets. The Fund will not usederivatives for speculation or for the purpose of leveraging (magnifying)investment returns.

The Fund may purchase money market instruments and certain derivatives inorder to manage cash flow into and out of the Fund, reduce the Fund’stransaction costs, or add value when these instruments are favorably priced.

The Fund may invest a small portion of its assets in equity futures and fixedincome futures, which are types of derivatives, and/or shares of stock and bondexchange-traded funds (ETFs). These futures and ETFs typically provide returnssimilar to those of stocks and bonds listed in the index, or in a subset of theindex, the Fund seeks to track. The Fund may purchase futures or ETFs whendoing so will reduce the Fund’s transaction costs, facilitate cash management,mitigate risk, or have the potential to add value because the instruments arefavorably priced. Vanguard receives no additional revenue from Fund assets

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invested in ETF Shares of other Vanguard funds. Fund assets invested in ETFShares are excluded when allocating to the Fund its share of the costs ofVanguard operations.

Cash ManagementThe 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, theFund 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, the Fund typically expects to meet redemptionswith positive cash flows. When this is not an option, the Fund seeks to maintainits risk exposure by selling a cross section of the Fund’s holdings to meetredemptions, while also factoring in transaction costs. Additionally, the Fund maywork with larger clients to implement their redemptions in a manner that is leastdisruptive 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 the 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. The 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, the Fundmay borrow money (subject to certain regulatory conditions and if availableunder board-approved procedures) through an interfund lending facility orthrough a bank line-of-credit, including a joint committed credit facility, in order tomeet redemption requests.

Temporary Investment MeasuresThe Fund may temporarily depart from its normal investment policies andstrategies when the 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, the Fund may invest beyond its normal limitsin derivatives or exchange-traded funds that are consistent with the Fund’s

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investment 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.

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.

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

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 Fund generally seeks to invest for the long term, it may sellsecurities regardless of how long they have been held. Generally, an index fundsells securities in response to redemption requests or to changes in thecomposition of its target index or in an effort to manage the fund’s duration. TheFinancial Highlights section of this prospectus shows historical turnover ratesfor the Fund. A turnover rate of 100%, for example, would mean that the Fundhad 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 Fund and Vanguard

The 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 Fund through its Equity Index andFixed Income Groups. As of December 31, 2019, Vanguard served as advisor forapproximately $5 trillion in assets. Vanguard provides investment advisoryservices to the Fund pursuant to the Funds’ Service Agreement and subject tothe supervision and oversight of the trustees and officers of the Fund.

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

Under the terms of an SEC exemption, the Fund’s 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 the Fund’s advisory arrangementswill be communicated to shareholders in writing. As the Fund’s sponsor andoverall manager, Vanguard may provide investment advisory services to the Fundat any time. Vanguard may also recommend to the board of trustees that anadvisor be hired, terminated, or replaced or that the terms of an existingadvisory agreement be revised. The Fund has filed an application seeking asimilar SEC exemption with respect to investment advisors that are whollyowned subsidiaries of Vanguard. If the exemption is granted, the Fund may relyon the new SEC relief.

For a discussion of why the board of trustees approved the 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 theFund are:

William A. Coleman, CFA, Portfolio Manager at Vanguard. He has worked ininvestment management since joining Vanguard in 2006 and has co-managedthe stock portion of the Fund since 2016. Education: B.S., King’s College; M.S.,Saint Joseph’s University.

Gerard C. O’Reilly, Principal of Vanguard. He has been with Vanguard since1992, has managed investment portfolios since 1994, and has co-managed thestock portion of the Fund since 2016. Education: B.S., Villanova University.

Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard’sFixed Income Indexing Americas. He has been with Vanguard since 1998, hasworked in investment management since 1999, has managed investmentportfolios since 2005, and has managed the bond portion of the Fund since2013. Education: B.S., Ohio Northern University; M.B.A., Lehigh University.

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

Dividends, Capital Gains, and Taxes

Fund DistributionsThe 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, the Fundmay occasionally make a supplemental distribution at some other time duringthe year.

You can receive distributions of income or capital gains in cash, or you can havethem automatically reinvested in more shares of the Fund. However, if you areinvesting through an employer-sponsored retirement or savings plan, yourdistributions 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 and dividends as well as capital gains from the fund’s sale ofinvestments. Income consists of both the dividends that the fund earns fromany stock holdings and the interest it receives from any money market andbond investments. Capital gains are realized whenever the fund sellssecurities for higher prices than it paid for them. These capital gains areeither short-term or long-term, depending on whether the fund held thesecurities for one year or less or for more than one 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 Fund’s 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.

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

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Foreign investors. Vanguard funds offered for sale in the United States(Vanguard U.S. funds), including the Fund offered in this prospectus, are notwidely available outside the United States. Non-U.S. investors should be awarethat 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, the Fund reserves the right to treatsuch day as a business day and calculate NAVs as of the close of regular tradingon the 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 Fund does not sell or redeem shares. However, onthose days the value of the 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. Debt securities held by a fund arevalued based on information furnished by an independent pricing service ormarket quotations. When a fund determines that pricing-service information ormarket quotations either are not readily available or do not accurately reflect thevalue of a security, the security is priced at its fair value (the amount that theowner might reasonably expect to receive upon the current sale of the security).

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The values of any foreign securities held by a fund are converted into U.S. 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, includinginstitutional 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. A fund may use fair-value pricingwith respect to its fixed income securities on bond market holidays when thefund is open for business (such as Columbus Day and Veterans Day).

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 (assuming reinvestment of all distributions).This information has been obtained from the financial statements audited byPricewaterhouseCoopers LLP, an independent registered public accounting firm,whose report, along with fund financial statements, is included in a fund’s mostrecent annual report to shareholders. You may obtain a free copy of a fund’slatest annual or semiannual report, which is available upon request.

Vanguard Balanced Index Fund Admiral Shares

Year Ended December 31,For a Share Outstanding Throughout Each Period 2019 2018 2017 2016 2015Net Asset Value, Beginning of Period $32.99 $34.72 $31.11 $29.22 $29.68

Investment Operations

Net Investment Income 0.8171 0.7911 0.6891 0.649 0.612Net Realized and Unrealized Gain (Loss) onInvestments

6.319 (1.757) 3.599 1.890 (0.460)

Total from Investment Operations 7.136 (0.966) 4.288 2.539 0.152Distributions

Dividends from Net Investment Income (0.830) (0.764) (0.678) (0.649) (0.612)Distributions from Realized Capital Gains (0.066) — — — —Total Distributions (0.896) (0.764) (0.678) (0.649) (0.612)Net Asset Value, End of Period $39.23 $32.99 $34.72 $31.11 $29.22

Total Return2 21.79% –2.86% 13.89% 8.77% 0.51%

Ratios/Supplemental Data

Net Assets, End of Period (Millions) $33,585 $23,913 $23,556 $18,695 $15,726Ratio of Total Expenses to Average Net Assets 0.07% 0.07% 0.07% 0.07% 0.08%Ratio of Net Investment Income to Average NetAssets

2.22% 2.26% 2.09% 2.18% 2.06%

Portfolio Turnover Rate3 37%4 44%4 37%4 44%4 61%

1 Calculated based on average shares outstanding.2 Total returns do not include account service fees that may have applied in the periods shown.3 Includes 6%, 10%, 11%, 12%, and 24%, attributable to mortgage-dollar-roll activity.4 Excludes the value of portfolio securities received or delivered as a result of in-kind purchases or redemptions of

the fund’s capital shares.

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Vanguard Balanced Index Fund Investor Shares

Year Ended December 31,For a Share Outstanding Throughout Each Period 2019 2018 2017 2016 2015Net Asset Value, Beginning of Period $32.99 $34.72 $31.11 $29.22 $29.68

Investment Operations

Net Investment Income 0.7551 0.7481 0.6471 0.613 0.570Net Realized and Unrealized Gain (Loss) on Investments 6.345 (1.753) 3.600 1.889 (0.459)Total from Investment Operations 7.100 (1.005) 4.247 2.502 0.111Distributions

Dividends from Net Investment Income (0.794) (0.725) (0.637) (0.612) (0.571)Distributions from Realized Capital Gains (0.066) — — — —Total Distributions (0.860) (0.725) (0.637) (0.612) (0.571)Net Asset Value, End of Period $39.23 $32.99 $34.72 $31.11 $29.22

Total Return2 21.67% –2.97% 13.75% 8.63% 0.37%

Ratios/Supplemental Data

Net Assets, End of Period (Millions) $396 $3,014 $3,474 $3,343 $3,090Ratio of Total Expenses to Average Net Assets 0.18% 0.18% 0.19% 0.19% 0.22%Ratio of Net Investment Income to Average Net Assets 2.11% 2.15% 1.97% 2.06% 1.92%Portfolio Turnover Rate3 37%4 44%4 37%4 44%4 61%

1 Calculated based on average shares outstanding.2 Total returns do not include account service fees that may have applied in the periods shown.3 Includes 6%, 10%, 11%, 12%, and 24%, attributable to mortgage-dollar-roll activity.4 Excludes the value of portfolio securities received or delivered as a result of in-kind purchases or redemptions of

the fund’s capital shares.

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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 Investor Shares

Investor Shares are generally available only to Vanguard funds that operate asfunds of funds and to certain retirement plan clients that receive recordkeepingservices from Vanguard.

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Account Minimums for Admiral SharesTo open and maintain an account. $3,000. Financial intermediaries,institutional clients, and Vanguard-advised clients should contact Vanguard forinformation on special eligibility rules that may apply to them regarding AdmiralShares. If you are investing through an intermediary, please contact that firmdirectly for more information regarding your eligibility.

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 share classes in this prospectus),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 KnowAdmiral Shares. Admiral Shares generally are not available for SIMPLE IRAs andVanguard Individual 401(k) Plans.

Check 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 received by Vanguard on a business day before theclose of regular trading on the NYSE (generally 4 p.m., Eastern time), the tradedate will be the same day. For a conversion request received on a business dayafter the close of regular trading on the NYSE, or on a nonbusiness day, the tradedate will be the next business day. See Other Rules You Should Know.

Conversions to Institutional SharesYou are eligible for a self-directed conversion from another share class toInstitutional Shares of the Fund, provided that your account meets all eligibilityrequirements. You may request a conversion through our website (if you areregistered for online access), or you may contact Vanguard by telephone or bymail to request this transaction. Accounts that qualify for Institutional Shares willnot be automatically converted.

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, as appropriate. A decline in the account balance because of marketmovement may result in such a conversion. Vanguard will notify the investor inwriting before any mandatory conversion occurs.

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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.

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.

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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.

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 regular

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trading 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.

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 the Fund within one business day of thetrade date; 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. By

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calling 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.

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.

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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.

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).

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• Transfers and reregistrations of shares within the same fund.

• Purchases of shares by asset transfer or direct rollover.

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

• Checkwriting redemptions.

• Section 529 college savings plans.

• Certain approved institutional portfolios and asset allocation programs, as 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.

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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 sharesby 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.

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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.

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.

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

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 available

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through that firm and to learn about other rules that may apply. Your financialintermediary can provide you with account information and any required taxforms. You may be required to pay a commission on purchases of mutual fundshares made through a financial 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.

Account Service FeeVanguard may charge a $20 account service fee on fund accounts that have abalance below $10,000 for any reason, including market fluctuation. The accountservice fee may be applied to both retirement and nonretirement fund accountsand may be assessed on fund accounts in all Vanguard funds, regardless of theaccount minimum. The fee, which will be collected by redeeming fund shares inthe amount of $20, will be deducted from fund accounts subject to the fee onceper calendar year.

If you elect to receive your statements and other materials electronically (i.e., bye-delivery), the account service fee will not be charged, so long as your electionremains in effect. You can make your e-delivery election on vanguard.com.

Beginning on January 1, 2021, you may elect to receive paper copies ofshareholder reports free of charge as noted on the cover of this prospectus.

Certain account types have alternative fee structures, including SIMPLE IRAs,Vanguard Retirement Investment Program pooled plans, and Vanguard Individual401(k) Plans.

Low-Balance AccountsThe Fund reserves the right to liquidate a fund account whose balance fallsbelow the account minimum for any reason, including market fluctuation. Thisliquidation policy applies to nonretirement fund accounts and accounts that areheld through intermediaries. Any such liquidation will be preceded by writtennotice to the 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 fee

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charged 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 theassets 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.

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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.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 Balanced Index Fund twice a year, in February and August. Thesereports include overviews of the financial markets and provide the followingspecific Fund information:

• Performance assessments and comparisons with industry benchmarks.

• Financial statements with listings of Fund holdings.

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

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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 the Fundas an investment option.

• If you have any questions about the Fund or Vanguard, including those aboutthe Fund’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 the Fund. Consult your recordkeeperor plan administrator for more information.

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

Balanced Index Fund

Investor Shares 11/09/1992 Balanced 02 921931101Admiral Shares 11/13/2000 BalAdml 502 921931200

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.

BLOOMBERG is a trademark and service mark of Bloomberg Finance L.P. BARCLAYS is a trademark and service markof Barclays Bank Plc, used under license. Bloomberg Finance L.P. and its affiliates, including Bloomberg Index ServicesLimited (BISL) (collectively, Bloomberg), or Bloomberg’s licensors, own all proprietary rights in the Bloomberg BarclaysU.S. Aggregate Float Adjusted Index (the Index or Bloomberg Barclays Index).

Neither Barclays Bank Plc, Barclays Capital Inc., or any affiliate (collectively Barclays) or Bloomberg is the issuer orproducer of the Balanced Index Fund and neither Bloomberg nor Barclays has any responsibilities, obligations orduties to investors in the Balanced Index Fund. The Index is licensed for use by The Vanguard Group, Inc. (Vanguard)as the sponsor of the Balanced Index Fund. Bloomberg and Barclays’ only relationship with Vanguard in respect to theIndex is the licensing of the Index, which is determined, composed and calculated by BISL, or any successor thereto,without regard to the Issuer or the Balanced Index Fund or the owners of the Balanced Index Fund.

Additionally, Vanguard may for itself execute transaction(s) with Barclays in or relating to the Index in connection withthe Balanced Index Fund. Investors acquire the Balanced Index Fund from Vanguard and investors neither acquire anyinterest in the Index nor enter into any relationship of any kind whatsoever with Bloomberg or Barclays upon makingan investment in the Balanced Index Fund. The Balanced Index Fund is not sponsored, endorsed, sold or promoted byBloomberg or Barclays. Neither Bloomberg nor Barclays makes any representation or warranty, express or impliedregarding the advisability of investing in the Balanced Index Fund or the advisability of investing in securitiesgenerally or the ability of the Index to track corresponding or relative market performance. Neither Bloomberg norBarclays has passed on the legality or suitability of the Balanced Index Fund with respect to any person or entity.Neither Bloomberg nor Barclays is responsible for and has not participated in the determination of the timing of,prices at, or quantities of the Balanced Index Fund to be issued. Neither Bloomberg nor Barclays has any obligation totake the needs of the Issuer or the owners of the Balanced Index Fund or any other third party into consideration indetermining, composing or calculating the Index. Neither Bloomberg nor Barclays has any obligation or liability inconnection with administration, marketing or trading of the Balanced Index Fund.

The licensing agreement between Bloomberg and Barclays is solely for the benefit of Bloomberg and Barclays and notfor the benefit of the owners of the Balanced Index Fund, investors or other third parties. In addition, the licensingagreement between Vanguard and Bloomberg is solely for the benefit of Vanguard and Bloomberg and not for thebenefit of the owners of the Balanced Index Fund, investors or other third parties.

NEITHER BLOOMBERG NOR BARCLAYS SHALL HAVE ANY LIABILITY TO THE ISSUER, INVESTORS OR TO OTHERTHIRD PARTIES FOR THE QUALITY, ACCURACY AND/OR COMPLETENESS OF THE BLOOMBERG BARCLAYS INDEX ORANY DATA INCLUDED THEREIN OR FOR INTERRUPTIONS IN THE DELIVERY OF THE BLOOMBERG BARCLAYS INDEX.NEITHER BLOOMBERG NOR BARCLAYS MAKES ANY WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BEOBTAINED BY THE ISSUER, THE INVESTORS OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THEBLOOMBERG BARCLAYS INDEX OR ANY DATA INCLUDED THEREIN. NEITHER BLOOMBERG NOR BARCLAYS MAKESANY EXPRESS OR IMPLIED WARRANTIES, AND EACH HEREBY EXPRESSLY DISCLAIMS ALL WARRANTIES OFMERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE WITH RESPECT TO ANY OF THE BLOOMBERGBARCLAYS INDEX OR ANY DATA INCLUDED THEREIN. BLOOMBERG RESERVES THE RIGHT TO CHANGE THEMETHODS OF CALCULATION OR PUBLICATION, OR TO CEASE THE CALCULATION OR PUBLICATION OF THEBLOOMBERG BARCLAYS INDEX, AND NEITHER BLOOMBERG NOR BARCLAYS SHALL BE LIABLE FOR ANYMISCALCULATION OF OR ANY INCORRECT, DELAYED OR INTERRUPTED PUBLICATION WITH RESPECT TO ANY OFTHE BLOOMBERG BARCLAYS INDEX. NEITHER BLOOMBERG NOR BARCLAYS SHALL BE LIABLE FOR ANY DAMAGES,INCLUDING, WITHOUT LIMITATION, ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY LOST

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PROFITS AND EVEN IF ADVISED OF THE POSSIBILITY OF SUCH, RESULTING FROM THE USE OF THE BLOOMBERGBARCLAYS INDEX OR ANY DATA INCLUDED THEREIN OR WITH RESPECT TO THE BALANCED INDEX FUND.

None of the information supplied by Bloomberg or Barclays and used in this publication may be reproduced in anymanner without the prior written permission of both Bloomberg and Barclays Capital, the investment banking divisionof Barclays Bank Plc. Barclays Bank Plc is registered in England No. 1026167. Registered office 1 Churchill PlaceLondon E14 5HP.

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Glossary of Investment Terms

Balanced Composite Index. An index that is weighted 60% MSCI US BroadMarket Index and 40% Bloomberg Barclays U.S. Aggregate Float Adjusted Indexthrough January 14, 2013; and 60% CRSP US Total Market Index and 40%Bloomberg Barclays U.S. Aggregate Float Adjusted Index thereafter.

Bond. A debt security (IOU) issued by a corporation, a government, or agovernment agency in exchange for the money the bondholder lends it. In mostinstances, the issuer agrees to pay back the loan by a specific date and generallyto make regular interest payments until that date.

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.

Coupon Rate. The interest rate paid by the issuer of a debt security until itsmaturity. It is expressed as an annual percentage of the face value ofthe security.

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

Duration. A measure of the sensitivity of bond—and bond fund—prices tointerest rate movements. For example, if a bond has a duration of two years, itsprice would fall by approximately 2% when interest rates rise by 1%. On theother hand, the bond’s price would rise by approximately 2% when interest ratesfall by 1%.

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.

Face Value. The amount to be paid at a bond’s maturity; also known as the parvalue or principal.

Fixed Income Security. An investment, such as a bond, representing a debt thatmust be repaid by a specified date, and on which the borrower must pay a fixed,variable, or floating rate of interest.

Float-Adjusted Index. An index that weights its constituent securities based onthe value of the constituent securities that are available for public trading, ratherthan the value of all constituent securities. Some portion of an issuer’s securities

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may be unavailable for public trading because, for example, those securities areowned by company insiders on a restricted basis or by a government agency. Byexcluding unavailable securities, float-adjusted indexes can produce a moreaccurate picture of the returns actually experienced by investors in themeasured market.

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.”

Investment-Grade Bond. A debt security whose credit quality is considered byindependent bond rating agencies, or through independent analysis conductedby a fund’s advisor, to be sufficient to ensure timely payment of principal andinterest under current economic circumstances. Debt securities rated in one ofthe four highest rating categories are considered investment-grade. Other debtsecurities may be considered by an advisor to be investment-grade.

Joint Committed Credit Facility. The 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 Fund’s 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 Broad Market Index. An index that tracks virtually all stocks that tradein the U.S. stock 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.

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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For More InformationIf you would like more information about VanguardBalanced Index Fund, the following documents areavailable free upon request:

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

Statement of Additional Information (SAI)The SAI provides more detailed information about theFund 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 Fund 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 participant in an employer-sponsored plan:Telephone: 800-523-1188; 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 Fund 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: publicinfo@sec.gov.

Fund’s Investment Company Act file number: 811-58431

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

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