SPI 223 Vanguard FTSE Social Index Fund

December 19, 2025

Summary Prospectus

Vanguard FTSE Social Index Fund

Institutional Shares

Vanguard FTSE Social Index Fund Institutional Shares (VFTNX)

The Fund’s statutory Prospectus and Statement of Additional Information dated December 19, 2025, as may be amended or supplemented, are incorporated into and made part of this Summary Prospectus by reference.

Before you invest, you may want to review the Fund’s Prospectus, which contains more information about the Fund and its risks. You can find the Fund’s Prospectus and other information about the Fund online at www.vanguard.com/prospectus and https://personal.vanguard.com/us/literature/reports/MFs. You can also obtain this information at no cost by calling 800-662-7447 (if you are an individual investor) or 800-523-1036 (if you are a client of Vanguard’s Institutional Division) or by sending an email request to online@vanguard.com.

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

Investment Objective

Vanguard FTSE Social Index Fund (the “Fund”) seeks to track the performance of a benchmark index that measures the investment return of large- and mid-capitalization stocks.

Fees and Expenses

The following tables describe the fees and expenses you may pay if you buy, hold, and sell Institutional Shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and example below.

Shareholder Fees
(Fees paid directly from your investment)


Sales Charge (Load) Imposed on Purchases	None
Purchase Fee	None
Sales Charge (Load) Imposed on Reinvested Dividends	None
Redemption Fee	None

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


Management Fees	0.06 %
12b-1 Distribution Fee	None
Other Expenses	0.01 %
Total Annual Fund Operating Expenses	0.07 %

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same.

1 Year	3 Years	5 Years	10 Years
$7	$23	$40	$90

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 higher taxes when Fund

shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 7% of the average value of its portfolio.

Principal Investment Strategies

The Fund employs an indexing investment approach designed to track the performance of the FTSE US Choice Index (the “Target Index”), a market capitalization-weighted index made up of large- and mid-cap stocks of companies that are screened for certain environmental, social, and corporate governance (ESG) criteria by the Index Provider, FTSE Russell. Under normal circumstances, the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in the stocks that make up the Target Index.

The Target Index excludes the stocks of companies that the Index Provider determines engage in, have a specified level of involvement in, and/or derive threshold amounts of revenue from certain activities or business segments related to the following: adult entertainment, alcohol, tobacco, cannabis, gambling, chemical and biological weapons, cluster munitions, anti-personnel landmines, nuclear weapons, conventional military weapons, civilian firearms, nuclear power, and coal, oil, or gas. The level or type of involvement in, or amount of revenue earned from, certain activities or business segments that lead to exclusion by the Index Provider can vary from one activity or business segment to another. The Target Index’s methodology also excludes the stocks of companies that, as the Index Provider determines based on its internal assessment, do not meet certain labor, human rights, environmental, and anti-corruption standards, as well as companies that do not meet certain diversity criteria. The components of the Target Index are likely to change over time.

The Fund attempts to replicate the Target Index by investing all, or substantially all, of its assets in the stocks that make up the Target Index, holding each stock in approximately the same proportion as its weighting in the Target Index. The Fund may become nondiversified, as defined under the Investment Company Act of 1940, solely as a result of tracking an index. This could occur due to events such as an index rebalance or market movement. A nondiversified fund may invest a greater percentage of its assets in the securities of particular issuers as compared with diversified funds. In addition, the Fund could become concentrated in an industry or group of industries if the Target Index becomes concentrated due to market conditions or the performance of a single or related group of issuers.

Principal Risks

As with any investment, an investment in the Fund could lose money over any time period. The Fund’s share price and total return may fluctuate, potentially within a wide range. The principal risks of investing in the Fund are summarized below. Each of the following risks could affect the Fund’s performance:

• ESG Investing. As described in the Fund’s principal investment strategies, the Index Provider excludes certain securities from the Target Index based on ESG criteria. As a result, the Fund’s investments could, in the aggregate, trail the returns of other funds that use ESG criteria or underperform the market as a whole. The Index Provider’s use of ESG criteria may result in the Target Index becoming focused, at times, in a particular market sector, which would subject the Fund to proportionately higher exposure to the risks of that sector. Interpretations of what it means for a company or issuer to exhibit ESG characteristics can—and do—vary significantly across individuals, index providers, advisors, and other funds that use ESG criteria. The Index Provider’s assessment of whether or not a company or issuer meets the ESG criteria used to construct the Target Index, or the ESG criteria itself, may not align with your personal view of what it means for a company or issuer to exhibit ESG characteristics generally. Further, individual securities held by the Fund may not reflect your personal preferences, beliefs, expectations, and/or values. In order to assess a company or issuer against the ESG criteria used to construct the Target Index, the Index Provider depends on the availability of data obtained through voluntary or third-party reporting. There can be no assurance that this data will be accurate, complete, or current, which could result in an inaccurate assessment of a company or issuer.

• General Market Risk. The markets in which the Fund invests can be affected by a variety of factors. These factors, which can be real or perceived, may include economic, market, political, and regulatory conditions and developments as well as local, regional, or global events such as wars, military conflicts, natural disasters, and public health issues. In addition, investor sentiment and expectations regarding these factors can also impact the markets. Different parts of the market, including different industries and sectors as well as different types of securities, may react differently to factors that affect the market. These factors can contribute to market uncertainty, market volatility, and fluctuations in the value of the Fund’s investments, thereby resulting in potential losses to the Fund over short or long periods.

• Investing in Equity Markets. The Fund invests in the equity markets. Equity markets have historically been cyclical, having periods of time when stock values rise and fall. Market volatility can lead to significant fluctuations in stock values, resulting in potential losses to the Fund.

• Market Capitalization (Market Cap). Companies are generally classified into three types of market cap depending on their size: small-, mid-, and large-cap. Companies can be further classified into micro- or mega-cap.

Different factors can affect each market cap uniquely, and historically small- and mid-cap stocks have typically been more volatile due to the effects of changing economic conditions. Large companies may not reach the same levels of growth or performance as smaller companies, and they may be slower to react to competitive challenges. The performance of funds that invest in a subset of market caps could diverge from the performance of a fund that is focused on a broader representation of the stock market.

• Index Investing. The Fund is subject to risks associated with index investing. Because the Fund generally seeks to track the performance of the Target Index regardless of how the Target Index is performing, the Fund’s performance may be lower than it would be if it were actively managed. Although the Fund seeks to hold substantially all of the securities included in the Target Index, it may be unable to do so. In addition, the Fund could be prevented from holding one or more securities in the same proportion as in the Target Index. The performance of the Fund’s investments, in the aggregate, may not match the investment performance of the Target Index. This risk, known as tracking error risk, may be heightened during times of increased market volatility or under other unusual market conditions. The Fund also could be negatively impacted by changes to the Target Index made by the Index Provider or by errors made by the Index Provider. Any gains, losses, or costs associated with or resulting from an error made by the Index Provider will generally be borne by the Fund and, as a result, the Fund’s shareholders.

• Nondiversification. By tracking its broad-based Target Index, the Fund could become nondiversified, as defined under the Investment Company Act of 1940, due to events such as an index rebalance or market movement. The performance of nondiversified funds may be negatively impacted by relatively few securities or even a single security and their shares may experience significant fluctuations in value.

• Concentration Risk. Except as may be necessary to approximate the composition of its Target Index, the Fund will not concentrate its investments in the securities of issuers whose principal business activities are in the same industry or group of industries. If the Target Index becomes concentrated and the Fund needs to concentrate in the same industry or group of industries, its performance could be negatively impacted by the industry or industries in which it is concentrated.

• Information Technology Sector. As of the Fund’s most recent fiscal year end, stocks of companies within the information technology sector made up a significant portion of the Target Index. As a result, the performance of the Target Index, and therefore the performance of the Fund, may be impacted by the general condition of the information technology sector.

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

Annual Total Returns

The following bar chart and table show the Fund’s historical performance and are intended to help you understand the risks of investing in the Fund. The bar chart shows how the performance of the Fund’s Institutional Shares has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Institutional Shares compare with those of a broad-based securities market index and one or more additional indexes with similar investment characteristics as 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.

Annual Total Returns — Vanguard FTSE Social Index Fund Institutional Shares1

1 The year-to-date return as of the most recent calendar quarter, which ended on September 30, 2025, was 14.55%.

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

	Total Return	Quarter
Highest	23.37 %	June 30, 2020
Lowest	-19.96 %	March 31, 2020

Average Annual Total Returns for Periods Ended December 31, 2024

	1 Year	5 Years	10 Years
Vanguard FTSE Social Index Fund Institutional Shares
Return Before Taxes	26.01 %	14.55 %	13.48 %
Return After Taxes on Distributions	25.68	14.22	13.09
Return After Taxes on Distributions and Sale of Fund Shares	15.60	11.64	11.20
FTSE US Choice Index (reflects no deduction for fees, expenses, or taxes)	26.14 %	14.67 %	13.59 %
FTSE USA Index (reflects no deduction for fees, expenses, or taxes)	25.10	14.47	13.04
Dow Jones U.S. Total Stock Market Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)	23.88	13.78	12.48

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

Aaron Choi, CFA, Portfolio Manager at Vanguard. He has co-managed the Fund since February 2025.

Chris Nieves, CFA, Portfolio Manager at Vanguard. He has co-managed the Fund since February 2025.

Gerard C. O’Reilly, Portfolio Manager and Principal of Vanguard. He has co-managed the Fund since 2015.

Purchase and Sale of Fund Shares

If you invest directly with Vanguard, you may purchase or redeem shares online through our website (vanguard.com), by mail (The Vanguard Group, P.O. Box 982901, El Paso, TX 79998-2901), or by telephone (800-662-2739). The minimum investment amount required to open a Fund account for Institutional

Shares is generally $5 million. The minimum investment amount required to add to an existing Fund account is generally $1.

If you invest in Vanguard fund shares through an employer-sponsored retirement or savings plan, your plan administrator or your benefits office can provide you with detailed information on how you can invest through your plan.

Tax Information

The Fund’s distributions may be taxable as ordinary income or capital gains. If you are investing through a tax-advantaged account, such as an IRA or an employer-sponsored retirement or savings plan, special tax rules apply. You should consult your own tax advisor with respect to any particular U.S. or non-U.S. tax consequences of your investment in the Fund.

Payments to Financial Intermediaries

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

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London Stock Exchange Group companies include FTSE International Limited (“FTSE”), Frank Russell Company (“Russell”), MTS Next Limited (“MTS”), and FTSE TMX Global Debt Capital Markets Inc. (“FTSE TMX”). All rights reserved. “FTSE®”, “Russell®”, “MTS®“, “FTSE TMX®” and “FTSE Russell” and other service marks and trademarks related to the FTSE or Russell indexes are trademarks of the London Stock Exchange Group companies and are used by FTSE, MTS, FTSE TMX and Russell under license. All information is provided for information purposes only. Every effort is made to ensure that all information given in this publication is accurate, but no responsibility or liability can be accepted by the London Stock Exchange Group companies nor its licensors for any errors or for any loss from use of this publication. Neither the London Stock Exchange Group companies nor any of their licensors make any claim, prediction, warranty or representation whatsoever, expressly or impliedly, either as to the results to be obtained from the use of the Indices or the fitness or suitability of the Indices for any particular purpose to which they might be put. The London Stock Exchange Group companies do not provide investment advice and nothing in this document should be taken as constituting financial or investment advice. The London Stock Exchange Group companies make no representation regarding the advisability of investing in any asset. A decision to invest in any such asset should not be made in reliance on any information herein. Indexes cannot be invested in directly. Inclusion of an asset in an index is not a recommendation to buy, sell or hold that asset. The general information contained in this publication should not be acted upon without obtaining specific legal, tax, and investment advice from a licensed professional. No part of this information may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior written permission of the London Stock Exchange Group companies. Distribution of the London Stock Exchange Group companies’ index values and the use of their indexes to create financial products require a license with FTSE, FTSE TMX, MTS and/or Russell and/or its licensors.

Vanguard FTSE Social Index Fund Institutional Shares—Fund Number 223

To request additional information about the Fund, please visit vanguard.com or contact us at 800-662-7447 (if you are an individual investor) or 800-523-1036 (if you are a client of Vanguard’s Institutional Division).

Vanguard Marketing Corporation, Distributor.

SPI 223 122025