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Fees and Expenses The following tables describe the fees and expenses you may pay if you buy, hold, and sell Institutional Shares or Institutional Plus 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 examples below. Shareholder Fees (Fees paid directly from your investment) 0 0 0 0 0 0 0 0 Annual Fund Operating Expenses (Expenses that you pay each year as a percentage of the value of your investment) 0.00031 0.0002 0 0 0.00004 0.0000 0.00035 0.0002 Examples These examples are intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. The examples assume 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 examples also assume that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. 4 11 20 45 2 6 11 26 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 examples, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 4% of the average value of its portfolio. 0.04 Principal Investment Strategies The Fund employs an indexing investment approach designed to track the performance of the S&P 500 Index (the “Target Index”), a widely recognized benchmark of U.S. stock market performance that is dominated by the stocks of large U.S. companies. 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 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 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. As with any investment, an investment in the Fund could lose money over any time period. • 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 the 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 share classes presented compare with those of a broad-based securities market index and one or more additional indexes with similar investment characteristics 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. 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 share classes presented compare with those of a broad-based securities market index and one or more additional indexes with similar investment characteristics 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. vanguard.com/performance Annual Total Returns — Vanguard Institutional Index Fund Institutional Shares During the periods shown in the bar chart, the highest and lowest returns for a calendar quarter were: Highest 0.2055 2020-06-30 Lowest -0.1960 2020-03-31 Average Annual Total Returns for Periods Ended December 31, 2025 0.1784 0.1439 0.1479 0.1721 0.1350 0.1398 0.1094 0.1134 0.1221 0.1786 0.1440 0.1480 0.1788 0.1442 0.1482 0.1705 0.1307 0.1421 Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are shown only for the Institutional Shares and may differ for each share class. After-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder. 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. 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. Fund Summary Investment Objective Vanguard Institutional Total Stock Market Index Fund (the “Fund”) seeks to track the performance of a benchmark index that measures the investment return of the overall stock market. Fees and Expenses The following tables describe the fees and expenses you may pay if you buy, hold, and sell Institutional Shares or Institutional Plus 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 examples below. Shareholder Fees (Fees paid directly from your investment) 0 0 0 0 0 0 0 0 Annual Fund Operating Expenses (Expenses that you pay each year as a percentage of the value of your investment) 0.0002 0.0002 0 0 0.0001 0.0000 0.0003 0.0002 Examples These examples are intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. The examples assume 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 examples also assume that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. 3 10 17 39 2 6 11 26 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 examples, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 5% of the average value of its portfolio. 0.05 Principal Investment Strategies The Fund employs an indexing investment approach designed to track the performance of the CRSP US Total Market Index (the “Target Index”), which represents approximately 100% of the investable U.S. stock market, as determined by the index provider. The Target Index includes large-, mid-, small-, and micro-cap stocks regularly traded on the New York Stock Exchange and Nasdaq. 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 Fund invests by sampling the Target Index, meaning that it holds a range of securities that, in the aggregate, approximates the full Target Index in terms of key risk factors and other characteristics. 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 it may invest in 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. As with any investment, an investment in the Fund could lose money over any time period. • 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. Additionally, because the Fund does not hold all of the securities included in the Target Index, it is subject to the risk that the representative sample of securities selected by the advisor will, in the aggregate, vary from the investment profile of the full 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. • Management of Certain Similar Funds. The name, investment objective, principal investment strategies, and risks of the Fund are similar to another separate fund managed by the Fund’s portfolio managers. However, the investment results of the Fund may be higher or lower than, and there is no guarantee that the investment results of the Fund will be comparable to, that other fund. • 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 share classes presented compare with those of a broad-based securities market index and one or more additional indexes with similar investment characteristics 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. 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 share classes presented compare with those of a broad-based securities market index and one or more additional indexes with similar investment characteristics 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. vanguard.com/performance Annual Total Returns — Vanguard Institutional Total Stock Market Index Fund Institutional Shares During the periods shown in the bar chart, the highest and lowest returns for a calendar quarter were: Highest 0.2211 2020-06-30 Lowest -0.2089 2020-03-31 Average Annual Total Returns for Periods Ended December 31, 2025 0.1715 0.1310 0.1427 0.1633 0.1203 0.1321 0.1059 0.1021 0.1162 0.1716 0.1310 0.1427 0.1715 0.1308 0.1425 0.1705 0.1307 0.1421 Actual after-tax returns depend on your tax situation and may differ from those shown in the preceding table. When after-tax returns are calculated, it is assumed that the shareholder was in the highest individual federal marginal income tax bracket at the time of each distribution of income or capital gains or upon redemption. State and local income taxes are not reflected in the calculations. Please note that after-tax returns are shown only for Institutional Shares and may differ for each share class. After-tax returns are not relevant for a shareholder who holds fund shares in a tax-deferred account, such as an individual retirement account or a 401(k) plan. Also, figures captioned Return After Taxes on Distributions and Sale of Fund Shares may be higher than other figures for the same period if a capital loss occurs upon redemption and results in an assumed tax deduction for the shareholder. 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. 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. 2026-04-28 Fund Summary Investment Objective Vanguard Ultra-Short Treasury ETF (the “Fund”) seeks to track the performance of a market-weighted Treasury Index with an ultra-short-term dollar-weighted average maturity. Fees and Expenses The following tables describe the fees and expenses you may pay if you buy, hold, and sell 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) 0 0 Annual Fund Operating Expenses (Expenses that you pay each year as a percentage of the value of your investment) 0.0003 0 0.0004 0.0007 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. 7 23 40 90 This example does not include the brokerage commissions that you may pay to buy and sell shares of the Fund. Portfolio Turnover The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in 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 fiscal period from February 7, 2025, to December 31, 2025, the Fund’s portfolio turnover rate was 0% of the average value of its portfolio. Principal Investment Strategies The Fund employs an indexing investment approach designed to track the performance of the Bloomberg Short Treasury Index (the “Target Index”), which includes fixed income securities issued by the U.S. Treasury (not including inflation-protected securities, floating rate securities, and certain other security types) that have maturities up to 12 months. Under normal circumstances, the Fund invests at least 80% of its assets, plus the amount of any borrowings for investment purposes, in the bonds that make up the Target Index.The Fund invests by sampling the Target Index, meaning that it holds a range of securities that, in the aggregate, approximates the full Target Index in terms of key risk factors and other characteristics. The Fund seeks to maintain a dollar-weighted average maturity consistent with that of the Target Index, which, under normal circumstances, is expected to be between 1 and 12 months. As of December 31, 2025, the dollar-weighted average maturity of the Target Index was 4 months. As with any investment, an investment in the Fund could lose money over any time period. • 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 Bond Markets. The Fund may be impacted by the general condition of the bond markets and by factors that affect bonds and bond issuers. For example, as a general rule, bond prices and interest rates move in opposite directions. When interest rates rise, bond prices tend to fall, and when interest rates fall, bond prices tend to go up. Bond income also is affected by changes in interest rates. Interest rates can rise or fall for a number of reasons, including, but not limited to, central bank monetary policy, inflationary or deflationary pressures, and changes in general market and economic conditions. Changing interest rates, including, but not limited to, rates that fall below zero, could have unpredictable effects on the overall market and may expose the bond markets in particular to heightened volatility and potential illiquidity. The degree to which the Fund is impacted by certain bond market risks may vary based on factors disclosed in its principal investment strategies, such as the types of bonds in which it invests and the overall credit quality, average maturity, and/or average duration of its bond holdings. • Interest Rate Risk. During periods of rising interest rates, bond prices overall may decline, which could result in a decline in the Fund’s value. The prices of longer-term bonds are more sensitive to changes in interest rates than the prices of shorter-term bonds. • Income Risk. During periods of falling interest rates, the Fund’s income may decline. The income paid by shorter-term bonds is subject to a higher degree of fluctuation than the income paid by longer-term bonds. • Credit Risk. Credit risk refers to the chance that an issuer will default (fail to meet its credit obligations) or fail to make payments in a timely manner, which could result in a loss to the Fund. In addition, negative perceptions of an issuer’s ability to make payments can cause the price of a security to decline. While all debt securities are subject to credit risk to some extent, those with higher credit quality ratings generally pose less credit risk than those with lower credit quality ratings. • Bond Liquidity Risk. If the Fund is unable to sell a security at an advantageous time or price, its returns may be reduced. There may be limited trading in the secondary market for certain debt securities, which could make them more difficult to value or sell. • 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. Additionally, because the Fund does not hold all of the securities included in the Target Index, it is subject to the risk that the representative sample of securities selected by the advisor will, in the aggregate, vary from the investment profile of the full 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. • ETF Share Trading. The Fund’s ETF shares are listed for trading on Nasdaq and individual investors may only buy and sell them on the secondary market at market prices. Although it is expected that the market price of an ETF share typically will approximate its net asset value (NAV), there may be times when the market price of an ETF share and its NAV differ significantly. Disruptions to creation and redemption transactions, the existence of significant market volatility, or potential lack of an active trading market for ETF shares (including through a trading halt), as well as other factors, may result in ETF shares trading significantly above (at a premium) or below (at a discount) the Fund’s NAV or the intraday value of the Fund’s holdings. Thus, you may pay more or less than NAV when you buy ETF shares on the secondary market, and you may receive more or less than NAV when you sell those shares. • Authorized Participants. Only Authorized Participants may engage in creation or redemption transactions directly with the Fund. The Fund has a limited number of financial institutions that may act as Authorized Participants. The Fund’s Authorized Participants are not obligated to engage in creation or redemption transactions. To the extent that the Fund’s Authorized Participants are unable to or choose not to proceed with creation and/or redemption transactions with respect to the Fund and no other Authorized Participants step forward to engage in creation or redemption transactions with the Fund, the Fund’s ETF shares may trade at a discount to NAV and possibly face trading halts and/or delisting. 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 Fund has not been in operation long enough to report a full calendar-year return. Performance information is available on our website at vanguard.com/performance. The Fund has not been in operation long enough to report a full calendar-year return. Performance information is available on our website at vanguard.com/performance. Fund Summary Investment Objective Vanguard 0-3 Month Treasury Bill ETF (the “Fund”) seeks to track the performance of a market-weighted Treasury Index with an ultra-short-term dollar-weighted average maturity. Fees and Expenses The following tables describe the fees and expenses you may pay if you buy, hold, and sell 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) 0 0 Annual Fund Operating Expenses (Expenses that you pay each year as a percentage of the value of your investment) 0.0005 0 0.0001 0.0006 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. 6 19 34 77 This example does not include the brokerage commissions that you may pay to buy and sell shares of the Fund. Portfolio Turnover The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in 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 fiscal period from February 7, 2025, to December 31, 2025, the Fund’s portfolio turnover rate was 0% of the average value of its portfolio. Principal Investment Strategies The Fund employs an indexing investment approach designed to track the performance of the Bloomberg U.S. Treasury Bills 0-3 Months Index (the “Target Index”), which includes bonds issued by the U.S. Treasury (not including inflation-protected securities, floating rate securities, and certain other security types), all with maturities of 3 months or less. Under normal circumstances, the Fund invests at least 80% of its assets, plus the amount of any borrowings for investment purposes, in the bonds that make up the Target Index.The Fund invests by sampling the Target Index, meaning that it holds a range of securities that, in the aggregate, approximates the full Target Index in terms of key risk factors and other characteristics. The Fund maintains a dollar-weighted average maturity consistent with that of the Target Index.The Fund seeks to maintain a dollar-weighted average maturity consistent with that of the Target Index, which, under normal circumstances, is expected to be under 3 months. As of December 31, 2025, the dollar-weighted average maturity of the Target Index was 1 month. As with any investment, an investment in the Fund could lose money over any time period. • 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 Bond Markets. The Fund may be impacted by the general condition of the bond markets and by factors that affect bonds and bond issuers. For example, as a general rule, bond prices and interest rates move in opposite directions. When interest rates rise, bond prices tend to fall, and when interest rates fall, bond prices tend to go up. Bond income also is affected by changes in interest rates. Interest rates can rise or fall for a number of reasons, including, but not limited to, central bank monetary policy, inflationary or deflationary pressures, and changes in general market and economic conditions. Changing interest rates, including, but not limited to, rates that fall below zero, could have unpredictable effects on the overall market and may expose the bond markets in particular to heightened volatility and potential illiquidity. The degree to which the Fund is impacted by certain bond market risks may vary based on factors disclosed in its principal investment strategies, such as the types of bonds in which it invests and the overall credit quality, average maturity, and/or average duration of its bond holdings. • Interest Rate Risk. During periods of rising interest rates, bond prices overall may decline, which could result in a decline in the Fund’s value. The prices of longer-term bonds are more sensitive to changes in interest rates than the prices of shorter-term bonds. • Income Risk. During periods of falling interest rates, the Fund’s income may decline. The income paid by shorter-term bonds is subject to a higher degree of fluctuation than the income paid by longer-term bonds. • Credit Risk. Credit risk refers to the chance that an issuer will default (fail to meet its credit obligations) or fail to make payments in a timely manner, which could result in a loss to the Fund. In addition, negative perceptions of an issuer’s ability to make payments can cause the price of a security to decline. While all debt securities are subject to credit risk to some extent, those with higher credit quality ratings generally pose less credit risk than those with lower credit quality ratings. • Bond Liquidity Risk. If the Fund is unable to sell a security at an advantageous time or price, its returns may be reduced. There may be limited trading in the secondary market for certain debt securities, which could make them more difficult to value or sell. • 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. Additionally, because the Fund does not hold all of the securities included in the Target Index, it is subject to the risk that the representative sample of securities selected by the advisor will, in the aggregate, vary from the investment profile of the full 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. • ETF Share Trading. The Fund’s ETF shares are listed for trading on Nasdaq and individual investors may only buy and sell them on the secondary market at market prices. Although it is expected that the market price of an ETF share typically will approximate its net asset value (NAV), there may be times when the market price of an ETF share and its NAV differ significantly. Disruptions to creation and redemption transactions, the existence of significant market volatility, or potential lack of an active trading market for ETF shares (including through a trading halt), as well as other factors, may result in ETF shares trading significantly above (at a premium) or below (at a discount) the Fund’s NAV or the intraday value of the Fund’s holdings. Thus, you may pay more or less than NAV when you buy ETF shares on the secondary market, and you may receive more or less than NAV when you sell those shares. • Authorized Participants. Only Authorized Participants may engage in creation or redemption transactions directly with the Fund. The Fund has a limited number of financial institutions that may act as Authorized Participants. The Fund’s Authorized Participants are not obligated to engage in creation or redemption transactions. To the extent that the Fund’s Authorized Participants are unable to or choose not to proceed with creation and/or redemption transactions with respect to the Fund and no other Authorized Participants step forward to engage in creation or redemption transactions with the Fund, the Fund’s ETF shares may trade at a discount to NAV and possibly face trading halts and/or delisting. 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 Fund has not been in operation long enough to report a full calendar-year return. Performance information is available on our website at vanguard.com/performance. The Fund has not been in operation long enough to report a full calendar-year return. Performance information is available on our website at vanguard.com/performance. None through Vanguard (Broker fees vary) None through Vanguard (Broker fees vary) The expense information shown in the table has been restated to reflect current fees.