Form 497K VANGUARD INDEX FUNDS

Investment Objective

The Fund seeks to track the performance of a benchmark index that measures the investment return of large-capitalization stocks.

Fees and Expenses

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

1 The expense information shown in the table reflects estimated amounts for the current fiscal year.

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Example

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

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 3% of the average value of its portfolio.

Principal Investment Strategies

The Fund employs an indexing investment approach designed to track the performance of the Standard & Poor‘s 500 Index, a widely recognized benchmark of U.S. stock market performance that is dominated by the stocks of large U.S. companies. The Fund attempts to replicate the target index by investing all, or substantially all, of its assets in the stocks that make up the Index, holding each stock in approximately the same proportion as its weighting in the Index.

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Principal Risks

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

• Stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Fund’s target index tracks a subset of the U.S. stock market, which could cause the Fund to perform differently from the overall stock market. In addition, the Fund’s target index may, at times, become focused in stocks of a particular market sector, which would subject the Fund to proportionately higher exposure to the risks of that sector.

• Investment style risk, which is the chance that returns from large-capitalization stocks will trail returns from the overall stock market. Large-cap stocks tend to go through cycles of doing better—or worse—than other segments of the stock market or the stock market in general. These periods have, in the past, lasted for as long as several years.

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

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Annual Total Returns

The following bar chart and table are intended to help you understand the risks of investing in the Fund. Because the Fund’s Institutional Select Shares have not yet begun operations, the information presented in the bar chart and table reflects the performance of the Admiral™ Shares of Vanguard 500 Index Fund. (Admiral Shares are offered through a separate prospectus.) Performance of the Fund‘s Institutional Select Shares would be substantially similar to that of the Admiral Shares because both share classes constitute an investment in the same portfolio of securities; their returns generally should differ only to the extent that the expenses of the two share classes differ. The bar chart shows how the performance of the Fund‘s Admiral Shares has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Admiral Shares compare with those of the Fund‘s target index, which has investment characteristics similar to those of the Fund. Keep in mind that the Fund’s past performance (before and after taxes) does not indicate how the Fund will perform in the future. Updated performance information is available on our website at vanguard.com/performance or by calling Vanguard toll-free at 800-662-7447.

Annual Total Returns — Vanguard 500 Index Fund Admiral Shares

During the periods shown in the bar chart, the highest return for a calendar quarter was 15.99% (quarter ended June 30, 2009), and the lowest return for a quarter was –21.92% (quarter ended December 31, 2008).

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

Investment Advisor

The Vanguard Group, Inc. (Vanguard)

Portfolio Managers

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

Scott E. Geiger, Portfolio Manager at Vanguard. He has co-managed the Fund since 2016.

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Purchase and Sale of Fund Shares

Institutional clients (such as defined contribution or benefit plans, endowments, foundations, and 529 plans) may purchase or redeem shares online (if you are registered for online access); through a trading platform; by mail (Vanguard, P.O. Box 1101, Valley Forge, PA 19482-1101); or by telephone (800-523-1036). The minimum investment amount required to open and maintain a Fund account for Institutional Select Shares is generally $5 billion. The minimum investment amount required to add to an existing Fund account is generally $1.

Tax Information

The Fund’s distributions may be taxable as ordinary income or capital gain. If you are investing through a tax-deferred retirement account, such as a 401(k) plan, special tax rules apply.

Payments to Financial Intermediaries

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

Vanguard 500 Index Fund Institutional Select Shares—Fund Number 1940

CFA^® is a registered trademark owned by CFA Institute.

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

S&P DOW JONES INDICES DOES NOT GUARANTEE THE ADEQUACY, ACCURACY, TIMELINESS AND/OR THE COMPLETENESS OF THE INDEX OR ANY DATA RELATED THERETO OR ANY COMMUNICATION, INCLUDING BUT NOT LIMITED TO, ORAL OR WRITTEN COMMUNICATION (INCLUDING ELECTRONIC COMMUNICATIONS) WITH RESPECT THERETO. S&P DOW JONES INDICES SHALL NOT BE SUBJECT TO ANY DAMAGES OR LIABILITY FOR ANY ERRORS, OMISSIONS, OR DELAYS THEREIN. S&P DOW JONES INDICES MAKE NO EXPRESS OR IMPLIED WARRANTIES, AND EXPRESSLY DISCLAIMS ALL WARRANTIES, OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE OR AS TO RESULTS TO BE OBTAINED BY VANGUARD, OWNERS OF THE VANGUARD 500 INDEX FUND, OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE INDEX OR WITH RESPECT TO ANY DATA RELATED THERETO. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT WHATSOEVER SHALL S&P DOW JONES INDICES BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES INCLUDING BUT NOT LIMITED TO, LOSS OF PROFITS, TRADING LOSSES, LOST TIME OR GOODWILL, EVEN IF THEY HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, WHETHER IN CONTRACT, TORT, STRICT LIABILITY, OR OTHERWISE. THERE ARE NO THIRD PARTY BENEFICIARIES OF ANY AGREEMENTS OR ARRANGEMENTS BETWEEN S&P DOW JONES INDICES AND VANGUARD, OTHER THAN THE LICENSORS OF S&P DOW JONES INDICES.

© 2016 The Vanguard Group, Inc. All rights reserved.
Vanguard Marketing Corporation, Distributor.

SPI 1940 042016