485BPOS
Vanguard Sector Bond Index Funds
Prospectus
December 22, 2023
Institutional Shares
Vanguard Short-Term Treasury Index Fund Institutional Shares (VSBIX)
Vanguard Intermediate-Term Treasury Index Fund Institutional Shares (VIIGX)
Vanguard Long-Term Treasury Index Fund Institutional Shares (VLGIX)
Vanguard Short-Term Corporate Bond Index Fund Institutional Shares (VSTBX)
Vanguard Intermediate-Term Corporate Bond Index Fund Institutional Shares (VICBX)
Vanguard Long-Term Corporate Bond Index Fund Institutional Shares (VLCIX)
Vanguard Mortgage-Backed Securities Index Fund Institutional Shares (VMBIX)

This prospectus contains financial data for the Funds through the fiscal year ended August 31, 2023.

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.

Contents

Vanguard Short-Term Treasury Index Fund
Investment Objective
The Fund seeks to track the performance of a market-weighted Treasury index with a short-term dollar-weighted average maturity.
Fees and Expenses
The following table describes 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 table 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
0.05
%
12b-1 Distribution Fee
None
Other Expenses
0.00
%
Total Annual Fund Operating Expenses
0.05
%
Example
The following example is intended to help you compare the cost of investing in the Fund’s Institutional Shares with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $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 were to 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:
1 Year
3 Years
5 Years
10 Years
$5
$16
$28
$64
1

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 81% 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 1-3 Year Index. This Index includes fixed income securities issued by the U.S. Treasury (not including inflation-protected securities, floating rate securities and certain other security types), all with maturities between 1 and 3 years.
The Fund invests by sampling the Index, meaning that it holds a range of securities that, in the aggregate, approximates the full Index in terms of key risk factors and other characteristics. All of the Fund’s investments will be selected through the sampling process, and under normal circumstances, at least 80% of the Fund’s assets will be invested in bonds included in the Index. The Fund maintains a dollar-weighted average maturity consistent with that of the Index. As of August 31, 2023, the dollar-weighted average maturity of the Index was 2 years.
Principal Risks
The Fund is designed for investors with a low tolerance for risk, but you could still lose money by investing in it. The Fund is subject to the following risks, which could affect the Fund's performance, and the level of risk may vary based on market conditions:
• Income risk, which is the chance that the Fund's income will decline because of falling interest rates. Income risk is generally high for short-term bond funds, so investors should expect the Fund’s monthly income to fluctuate accordingly.
• Interest rate risk, which is the chance that bond prices overall will decline because of rising interest rates. Interest rate risk should be low for the Fund because it invests primarily in short-term bonds, whose prices are less sensitive to interest rate changes than are the prices of longer-term bonds.
• Index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low.
2

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 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 the Fund‘s target index and other comparative indexes, which have investment characteristics similar to those of the Fund. The Spliced Bloomberg U.S. Treasury 1-3 Year Index reflects the performance of the Bloomberg U.S. 1-3 Year Government Float Adjusted Index through December 11, 2017, and the Bloomberg U.S. Treasury 1-3 Year Index thereafter. 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 Short-Term Treasury Index Fund Institutional Shares1

1 The year-to-date return as of the most recent calendar quarter, which ended on September 30, 2023, was 1.71%.
During the periods shown in the bar chart, the highest and lowest returns for a calendar quarter were:
 
Total Return
Quarter
Highest
2.74
%
March 31, 2020
Lowest
-2.50
%
March 31, 2022
3

Average Annual Total Returns for Periods Ended December 31, 2022
 
1 Year
5 Years
10 Years
Vanguard Short-Term Treasury Index Fund
Institutional Shares
Return Before Taxes
-3.87
%
0.68
%
0.60
%
Return After Taxes on Distributions
-4.31
0.08
0.15
Return After Taxes on Distributions and Sale of Fund Shares
-2.29
0.28
0.27
Bloomberg U.S. Treasury 1-3 Year Index
(reflects no deduction for fees, expenses, or taxes)
-3.82
%
0.74
%
0.65
%
Spliced Bloomberg U.S. Treasury 1-3 Year Index in USD
(reflects no deduction for fees, expenses, or taxes)
-3.82
0.74
0.66
Bloomberg U.S. Aggregate Float Adjusted Index
(reflects no deduction for fees, expenses, or taxes)
-13.07
0.06
1.08
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 Manager
Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard’s Fixed Income Indexing Americas. He has managed the Fund since 2013.
4

Purchase and Sale of Fund Shares
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 and maintain a Fund account for Institutional Shares is $5 million. The minimum investment amount required to add to an existing Fund account is generally $1. If you are investing 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 gain. 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.
Payments to Financial Intermediaries
The Fund and its investment advisor do not pay financial intermediaries for sales of Fund shares.
5

Vanguard Intermediate-Term Treasury Index Fund
Investment Objective
The Fund seeks to track the performance of a market-weighted Treasury index with an intermediate-term dollar-weighted average maturity.
Fees and Expenses
The following table describes 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 table 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
0.04
%
12b-1 Distribution Fee
None
Other Expenses
0.01
%
Total Annual Fund Operating Expenses
0.05
%
Example
The following example is intended to help you compare the cost of investing in the Fund’s Institutional Shares with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $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 were to 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:
1 Year
3 Years
5 Years
10 Years
$5
$16
$28
$64
6

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 36% 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 3-10 Year Index. This Index includes fixed income securities issued by the U.S. Treasury (not including inflation-protected bonds, floating rate securities and certain other security types), with maturities between 3 and 10 years.
The Fund invests by sampling the Index, meaning that it holds a range of securities that, in the aggregate, approximates the full Index in terms of key risk factors and other characteristics. All of the Fund’s investments will be selected through the sampling process, and under normal circumstances, at least 80% of the Fund’s assets will be invested in bonds included in the Index. The Fund maintains a dollar-weighted average maturity consistent with that of the Index. As of August 31, 2023, the dollar-weighted average maturity of the Index was 5.6 years.
Principal Risks
An investment in the Fund could lose money over short or long periods of time. You should expect the Fund's share price and total return to fluctuate within a wide range. The Fund is subject to the following risks, which could affect the Fund's performance, and the level of risk may vary based on market conditions:
• Interest rate risk, which is the chance that bond prices overall will decline because of rising interest rates. Interest rate risk should be moderate for the Fund because it invests primarily in short- and intermediate-term bonds, whose prices are less sensitive to interest rate changes than are the prices of long-term bonds.
• Income risk, which is the chance that the Fund's income will decline because of falling interest rates. Income risk is generally moderate for intermediate-term bond funds, so investors should expect the Fund’s monthly income to fluctuate accordingly.
7

• Index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low.
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 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 the Fund‘s target index and other comparative indexes, which have investment characteristics similar to those of the Fund. The Spliced Bloomberg U.S. Treasury 3-10 Year Index reflects the performance of the Bloomberg U.S. 3-10 Year Government Float Adjusted Index through December 11, 2017, and the Bloomberg U.S. Treasury 3-10 Year Index thereafter. 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 Intermediate-Term Treasury Index Fund Institutional Shares1

1 The year-to-date return as of the most recent calendar quarter, which ended on September 30, 2023, was -0.54%.
During the periods shown in the bar chart, the highest and lowest returns for a calendar quarter were:
 
Total Return
Quarter
Highest
7.07
%
March 31, 2020
Lowest
-5.28
%
March 31, 2022
8

Average Annual Total Returns for Periods Ended December 31, 2022
 
1 Year
5 Years
10 Years
Vanguard Intermediate-Term Treasury Index Fund
Institutional Shares
Return Before Taxes
-10.65
%
0.18
%
0.68
%
Return After Taxes on Distributions
-11.25
-0.59
-0.06
Return After Taxes on Distributions and Sale of Fund Shares
-6.29
-0.14
0.22
Bloomberg U.S. Treasury 3-10 Year Index
(reflects no deduction for fees, expenses, or taxes)
-10.50
%
0.27
%
0.74
%
Spliced Bloomberg U.S. Treasury 3-10 Year Index in USD
(reflects no deduction for fees, expenses, or taxes)
-10.50
0.27
0.75
Bloomberg U.S. Aggregate Float Adjusted Index
(reflects no deduction for fees, expenses, or taxes)
-13.07
0.06
1.08
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.
9

Investment Advisor
The Vanguard Group, Inc. (Vanguard)
Portfolio Manager
Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard’s Fixed Income Indexing Americas. He has managed the Fund since 2013.
Purchase and Sale of Fund Shares
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 and maintain a Fund account for Institutional Shares is $5 million. The minimum investment amount required to add to an existing Fund account is generally $1. If you are investing 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 gain. 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.
Payments to Financial Intermediaries
The Fund and its investment advisor do not pay financial intermediaries for sales of Fund shares.
10

Vanguard Long-Term Treasury Index Fund
Investment Objective
The Fund seeks to track the performance of a market-weighted Treasury index with a long-term dollar-weighted average maturity.
Fees and Expenses
The following table describes 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 table 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
0.04
%
12b-1 Distribution Fee
None
Other Expenses
0.01
%
Total Annual Fund Operating Expenses
0.05
%
Example
The following example is intended to help you compare the cost of investing in the Fund’s Institutional Shares with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $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 were to 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:
1 Year
3 Years
5 Years
10 Years
$5
$16
$28
$64
11

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 20% 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. Long Treasury Index. This Index includes fixed income securities issued by the U.S. Treasury (not including inflation-protected bonds, floating rate securities and certain other security types), with maturities greater than 10 years.
The Fund invests by sampling the Index, meaning that it holds a range of securities that, in the aggregate, approximates the full Index in terms of key risk factors and other characteristics. All of the Fund’s investments will be selected through the sampling process, and under normal circumstances, at least 80% of the Fund’s assets will be invested in bonds included in the Index. The Fund maintains a dollar-weighted average maturity consistent with that of the Index. As of August 31, 2023, the dollar-weighted average maturity of the Index was 22.9 years.
Principal Risks
An investment in the Fund could lose money over short or long periods of time. You should expect the Fund's share price and total return to fluctuate within a wide range. The Fund is subject to the following risks, which could affect the Fund's performance, and the level of risk may vary based on market conditions:
• Interest rate risk, which is the chance that bond prices overall will decline because of rising interest rates. Interest rate risk should be high for the Fund because it invests primarily in long-term bonds, whose prices are more sensitive to interest rate changes than are the prices of shorter-term bonds.
• Income risk, which is the chance that the Fund's income will decline because of falling interest rates. Income risk should be low for the Fund because it invests primarily in long-term bonds.
• Index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low.
12

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 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 the Fund‘s target index and other comparative indexes, which have investment characteristics similar to those of the Fund. The Spliced Bloomberg U.S. Long Treasury Index reflects the performance of the Bloomberg U.S. Long Government Float Adjusted Index through December 11, 2017, and the Bloomberg U.S. Long Treasury Index thereafter. 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 Long-Term Treasury Index Fund Institutional Shares1

1 The year-to-date return as of the most recent calendar quarter, which ended on September 30, 2023, was -7.94%.
During the periods shown in the bar chart, the highest and lowest returns for a calendar quarter were:
 
Total Return
Quarter
Highest
20.86
%
March 31, 2020
Lowest
-13.44
%
March 31, 2021
13

Average Annual Total Returns for Periods Ended December 31, 2022
 
1 Year
5 Years
10 Years
Vanguard Long-Term Treasury Index Fund
Institutional Shares
Return Before Taxes
-29.45
%
-2.37
%
0.51
%
Return After Taxes on Distributions
-30.16
-3.30
-0.56
Return After Taxes on Distributions and Sale of Fund Shares
-17.38
-2.07
-0.02
Bloomberg U.S. Long Treasury Bond Index
(reflects no deduction for fees, expenses, or taxes)
-29.26
%
-2.20
%
0.60
%
Spliced Bloomberg U.S. Long Treasury Index in USD
(reflects no deduction for fees, expenses, or taxes)
-29.26
-2.20
0.61
Bloomberg U.S. Aggregate Float Adjusted Index
(reflects no deduction for fees, expenses, or taxes)
-13.07
0.06
1.08
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 Manager
Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard’s Fixed Income Indexing Americas. He has managed the Fund since 2013.
14

Purchase and Sale of Fund Shares
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 and maintain a Fund account for Institutional Shares is $5 million. The minimum investment amount required to add to an existing Fund account is generally $1. If you are investing 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 gain. 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.
Payments to Financial Intermediaries
The Fund and its investment advisor do not pay financial intermediaries for sales of Fund shares.
15

Vanguard Short-Term Corporate Bond Index Fund
Investment Objective
The Fund seeks to track the performance of a market-weighted corporate bond index with a short-term dollar-weighted average maturity.
Fees and Expenses
The following table describes 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 table 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
0.05
%
12b-1 Distribution Fee
None
Other Expenses
0.00
%
Total Annual Fund Operating Expenses
0.05
%
Example
The following example is intended to help you compare the cost of investing in the Fund’s Institutional Shares with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $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 were to 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:
1 Year
3 Years
5 Years
10 Years
$5
$16
$28
$64
16

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 63% 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. 1-5 Year Corporate Bond Index. This Index includes U.S. dollar-denominated, investment-grade, fixed-rate, taxable securities issued by U.S. and non-U.S. industrial, utility, and financial companies, with maturities between 1 and 5 years.
The Fund invests by sampling the Index, meaning that it holds a range of securities that, in the aggregate, approximates the full Index in terms of key risk factors and other characteristics. All of the Fund’s investments will be selected through the sampling process, and under normal circumstances, at least 80% of the Fund’s assets will be invested in bonds included in the Index. The Fund maintains a dollar-weighted average maturity consistent with that of the Index. As of August 31, 2023, the dollar-weighted average maturity of the Index was 2.9 years.
Principal Risks
The Fund is designed for investors with a low tolerance for risk, but you could still lose money by investing in it. The Fund is subject to the following risks, which could affect the Fund's performance, and the level of risk may vary based on market conditions:
• Credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline. Credit risk should be moderate for the Fund.
• Income risk, which is the chance that the Fund's income will decline because of falling interest rates. Income risk is generally high for short-term bond funds, so investors should expect the Fund’s monthly income to fluctuate accordingly.
• Interest rate risk, which is the chance that bond prices overall will decline because of rising interest rates. Interest rate risk should be low for the Fund
17

because it invests primarily in short-term bonds, whose prices are less sensitive to interest rate changes than are the prices of longer-term bonds.
• Liquidity risk, which is the chance that the Fund may not be able to sell a security in a timely manner at a desired price.
• Index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low.
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 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 the Fund‘s target index and a comparative index, which have 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 Short-Term Corporate Bond Index Fund Institutional Shares1

1 The year-to-date return as of the most recent calendar quarter, which ended on September 30, 2023, was 2.04%.
18

During the periods shown in the bar chart, the highest and lowest returns for a calendar quarter were:
 
Total Return
Quarter
Highest
5.57
%
June 30, 2020
Lowest
-3.70
%
March 31, 2022
Average Annual Total Returns for Periods Ended December 31, 2022
 
1 Year
5 Years
10 Years
Vanguard Short-Term Corporate Bond Index Fund
Institutional Shares
Return Before Taxes
-5.73
%
1.24
%
1.60
%
Return After Taxes on Distributions
-6.48
0.30
0.67
Return After Taxes on Distributions and Sale of Fund Shares
-3.39
0.56
0.82
Bloomberg U.S. 1-5 Year Corporate Bond Index
(reflects no deduction for fees, expenses, or taxes)
-5.62
%
1.35
%
1.70
%
Bloomberg U.S. Aggregate Float Adjusted Index
(reflects no deduction for fees, expenses, or taxes)
-13.07
0.06
1.08
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 Manager
Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard’s Fixed Income Indexing Americas. He has managed the Fund since its inception in 2009.
19

Purchase and Sale of Fund Shares
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 and maintain a Fund account for Institutional Shares is $5 million. The minimum investment amount required to add to an existing Fund account is generally $1. If you are investing 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 gain. 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.
Payments to Financial Intermediaries
The Fund and its investment advisor do not pay financial intermediaries for sales of Fund shares.
20

Vanguard Intermediate-Term Corporate Bond Index Fund
Investment Objective
The Fund seeks to track the performance of a market-weighted corporate bond index with an intermediate-term dollar-weighted average maturity.
Fees and Expenses
The following table describes 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 table and example below.
Shareholder Fees
(Fees paid directly from your investment)
 
Sales Charge (Load) Imposed on Purchases
None
Purchase Fee
0.25
%
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
0.05
%
12b-1 Distribution Fee
None
Other Expenses
0.00
%
Total Annual Fund Operating Expenses
0.05
%
Example
The following example is intended to help you compare the cost of investing in the Fund’s Institutional Shares with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $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 were to 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:
1 Year
3 Years
5 Years
10 Years
$30
$41
$53
$89
21

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 76% 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. 5-10 Year Corporate Bond Index. This Index includes U.S. dollar-denominated, investment-grade, fixed-rate, taxable securities issued by U.S. and non-U.S. industrial, utility, and financial companies, with maturities between 5 and 10 years.
The Fund invests by sampling the Index, meaning that it holds a range of securities that, in the aggregate, approximates the full Index in terms of key risk factors and other characteristics. All of the Fund’s investments will be selected through the sampling process, and under normal circumstances, at least 80% of the Fund’s assets will be invested in bonds included in the Index. The Fund maintains a dollar-weighted average maturity consistent with that of the Index. As of August 31, 2023, the dollar-weighted average maturity of the Index was 7.5 years.
Principal Risks
An investment in the Fund could lose money over short or long periods of time. You should expect the Fund's share price and total return to fluctuate within a wide range. The Fund is subject to the following risks, which could affect the Fund's performance, and the level of risk may vary based on market conditions:
• Credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline. Credit risk should be moderate for the Fund.
• Interest rate risk, which is the chance that bond prices overall will decline because of rising interest rates. Interest rate risk should be moderate for the Fund because it invests primarily in intermediate-term bonds, whose prices are less sensitive to interest rate changes than are the prices of long-term bonds.
• Income risk, which is the chance that the Fund's income will decline because of falling interest rates. Income risk is generally moderate for intermediate-term
22

bond funds, so investors should expect the Fund’s monthly income to fluctuate accordingly.
• Liquidity risk, which is the chance that the Fund may not be able to sell a security in a timely manner at a desired price.
• Index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low.
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 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 (including annual fund operating expenses but excluding shareholder fees) has varied from one calendar year to another over the periods shown. If applicable shareholder fees were reflected, returns would be less than those shown in the bar chart. The table shows how the average annual total returns of the Institutional Shares (including annual fund operating expenses and any applicable shareholder fees) compare with those of the Fund‘s target index and a comparative index, which have 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 Intermediate-Term Corporate Bond Index Fund Institutional Shares1

1 The year-to-date return as of the most recent calendar quarter, which ended on September 30, 2023, was 0.49%.
23

During the periods shown in the bar chart, the highest and lowest returns for a calendar quarter were:
 
Total Return
Quarter
Highest
9.63
%
June 30, 2020
Lowest
-6.96
%
March 31, 2022
Average Annual Total Returns for Periods Ended December 31, 2022
 
1 Year
5 Years
10 Years
Vanguard Intermediate-Term Corporate Bond Index Fund
Institutional Shares
Return Before Taxes
-14.27
%
0.72
%
2.07
%
Return After Taxes on Distributions
-15.28
-0.53
0.70
Return After Taxes on Distributions and Sale of Fund Shares
-8.43
0.07
1.01
Bloomberg U.S. 5-10 Year Corporate Bond Index
(reflects no deduction for fees, expenses, or taxes)
-13.89
%
0.89
%
2.18
%
Bloomberg U.S. Aggregate Float Adjusted Index
(reflects no deduction for fees, expenses, or taxes)
-13.07
0.06
1.08
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 Manager
Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard’s Fixed Income Indexing Americas. He has managed the Fund since its inception in 2009.
24

Purchase and Sale of Fund Shares
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 and maintain a Fund account for Institutional Shares is $5 million. The minimum investment amount required to add to an existing Fund account is generally $1. If you are investing 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 gain. 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.
Payments to Financial Intermediaries
The Fund and its investment advisor do not pay financial intermediaries for sales of Fund shares.
25

Vanguard Long-Term Corporate Bond Index Fund
Investment Objective
The Fund seeks to track the performance of a market-weighted corporate bond index with a long-term dollar-weighted average maturity.
Fees and Expenses
The following table describes 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 table and example below.
Shareholder Fees
(Fees paid directly from your investment)
 
Sales Charge (Load) Imposed on Purchases
None
Purchase Fee
1.00
%
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
0.04
%
12b-1 Distribution Fee
None
Other Expenses
0.01
%
Total Annual Fund Operating Expenses
0.05
%
Example
The following example is intended to help you compare the cost of investing in the Fund’s Institutional Shares with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $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 were to 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:
1 Year
3 Years
5 Years
10 Years
$105
$116
$128
$164
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 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 33% 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. 10+ Year Corporate Bond Index. This Index includes U.S. dollar-denominated, investment-grade, fixed-rate, taxable securities issued by U.S. and non-U.S. industrial, utility, and financial companies, with maturities greater than 10 years.
The Fund invests by sampling the Index, meaning that it holds a range of securities that, in the aggregate, approximates the full Index in terms of key risk factors and other characteristics. All of the Fund’s investments will be selected through the sampling process, and under normal circumstances, at least 80% of the Fund’s assets will be invested in bonds included in the Index. The Fund maintains a dollar-weighted average maturity consistent with that of the Index. As of August 31, 2023, the dollar-weighted average maturity of the Index was 22.9 years.
Principal Risks
An investment in the Fund could lose money over short or long periods of time. You should expect the Fund's share price and total return to fluctuate within a wide range. The Fund is subject to the following risks, which could affect the Fund's performance, and the level of risk may vary based on market conditions:
• Interest rate risk, which is the chance that bond prices overall will decline because of rising interest rates. Interest rate risk should be high for the Fund because it invests primarily in long-term bonds, whose prices are more sensitive to interest rate changes than are the prices of shorter-term bonds.
• Credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline. Credit risk should be moderate for the Fund.
• Liquidity risk, which is the chance that the Fund may not be able to sell a security in a timely manner at a desired price.
27

• Income risk, which is the chance that the Fund's income will decline because of falling interest rates. Income risk should be low for the Fund because it invests primarily in long-term bonds.
• Index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low.
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 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 (including annual fund operating expenses but excluding shareholder fees) has varied from one calendar year to another over the periods shown. If applicable shareholder fees were reflected, returns would be less than those shown in the bar chart. The table shows how the average annual total returns of the Institutional Shares (including annual fund operating expenses and any applicable shareholder fees) compare with those of the Fund's target index and a comparative index, which have 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 Long-Term Corporate Bond Index Fund Institutional Shares1

1 The year-to-date return as of the most recent calendar quarter, which ended on September 30, 2023, was -2.43%.
28

During the periods shown in the bar chart, the highest and lowest returns for a calendar quarter were:
 
Total Return
Quarter
Highest
11.28
%
June 30, 2020
Lowest
-12.79
%
June 30, 2022
Average Annual Total Returns for Periods Ended December 31, 2022
 
1 Year
5 Years
10 Years
Vanguard Long-Term Corporate Bond Index Fund
Institutional Shares
Return Before Taxes
-26.46
%
-1.05
%
2.14
%
Return After Taxes on Distributions
-27.67
-2.57
0.39
Return After Taxes on Distributions and Sale of Fund Shares
-15.62
-1.34
0.90
Bloomberg U.S. 10+ Year Corporate Bond Index
(reflects no deduction for fees, expenses, or taxes)
-25.62
%
-0.75
%
2.23
%
Bloomberg U.S. Aggregate Float Adjusted Index
(reflects no deduction for fees, expenses, or taxes)
-13.07
0.06
1.08
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 Manager
Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard’s Fixed Income Indexing Americas. He has managed the Fund since its inception in 2009.
29

Purchase and Sale of Fund Shares
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 and maintain a Fund account for Institutional Shares is $5 million. The minimum investment amount required to add to an existing Fund account is generally $1. If you are investing 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 gain. 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.
Payments to Financial Intermediaries
The Fund and its investment advisor do not pay financial intermediaries for sales of Fund shares.
30

Vanguard Mortgage-Backed Securities Index Fund
Investment Objective
The Fund seeks to track the performance of a market-weighted mortgage-backed securities index.
Fees and Expenses
The following table describes 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 table 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
0.04
%
12b-1 Distribution Fee
None
Other Expenses
0.01
%
Total Annual Fund Operating Expenses
0.05
%
Example
The following example is intended to help you compare the cost of investing in the Fund’s Institutional Shares with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $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 were to 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:
1 Year
3 Years
5 Years
10 Years
$5
$16
$28
$64
31

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 101% 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. MBS Float Adjusted Index. This Index covers U.S. agency mortgage-backed pass-through securities issued by the Government National Mortgage Association (GNMA), the Federal National Mortgage Association (FNMA), and the Federal Home Loan Mortgage Corporation (FHLMC). To be included in the Index, pool aggregates must have at least $1 billion currently outstanding and a weighted average maturity of at least 1 year.
The Fund invests by sampling the Index, meaning that it holds a range of securities that, in the aggregate, approximates the full Index in terms of key risk factors and other characteristics. All of the Fund’s investments will be selected through the sampling process, and under normal circumstances, at least 80% of the Fund’s assets will be invested in bonds included in the Index. The Fund maintains a dollar-weighted average maturity consistent with that of the Index. As of August 31, 2023, the dollar-weighted average maturity of the Index was 7.8 years.
Principal Risks
An investment in the Fund could lose money over short or long periods of time. You should expect the Fund's share price and total return to fluctuate within a wide range. The Fund is subject to the following risks, which could affect the Fund's performance, and the level of risk may vary based on market conditions:
• Prepayment risk, which is the chance that during periods of falling interest rates, homeowners will refinance their mortgages before their maturity dates, resulting in prepayment of mortgage-backed securities held by the Fund. The Fund would then lose any price appreciation above the mortgage’s principal and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund's income. Such prepayments and subsequent reinvestments would also increase the Fund’s portfolio turnover rate. Prepayment risk is high for the Fund.
32

• Extension risk, which is the chance that during periods of rising interest rates, homeowners will repay their mortgages at slower rates. This will lengthen the duration or average life of mortgage-backed securities held by the Fund and delay the Fund’s ability to reinvest proceeds at higher interest rates. Extension risk is high for the Fund.
• Interest rate risk, which is the chance that bond prices overall will decline because of rising interest rates. In addition, when interest rates decline, mortgage-backed securities’ prices typically do not rise as much as the prices of comparable bonds. This is because the market tends to discount mortgage-backed securities’ prices for prepayment risk when interest rates decline. Interest rate risk should be moderate for the Fund.
• Income risk, which is the chance that the Fund's income will decline because of falling interest rates. Income risk is generally moderate for intermediate-term bond funds, so investors should expect the Fund’s monthly income to fluctuate accordingly.
• Credit risk, which is the chance that the issuer of a mortgage-backed security will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline. Credit risk should be very low for the Fund because it invests in securities issued by U.S. government agencies and instrumentalities, including many securities backed by the full faith and credit of the U.S. government.
• Liquidity risk, which is the chance that the Fund may not be able to sell a security in a timely manner at a desired price.
• Index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low.
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 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 the Fund's target index and a comparative index, which have investment characteristics similar to those of the Fund. Keep in mind that the Fund's past performance (before and after taxes)
33

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 Mortgage-Backed Securities Index Fund Institutional Shares1

1 The year-to-date return as of the most recent calendar quarter, which ended on September 30, 2023, was -2.17%.
During the periods shown in the bar chart, the highest and lowest returns for a calendar quarter were:
 
Total Return
Quarter
Highest
3.20
%
March 31, 2020
Lowest
-5.21
%
September 30, 2022
Average Annual Total Returns for Periods Ended December 31, 2022
 
1 Year
5 Years
Since
Fund
Inception
Fund
Inception
Date
Vanguard Mortgage-Backed Securities
Index Fund Institutional Shares
10/31/2013
Return Before Taxes
-11.56
%
-0.60
%
0.75
%
Return After Taxes on Distributions
-12.36
-1.47
-0.13
Return After Taxes on Distributions and Sale
of Fund Shares
-6.83
-0.79
0.21
Bloomberg U.S. MBS Float Adjusted Index
(reflects no deduction for fees, expenses,
or taxes)
-11.45
%
-0.49
%
0.83
%
Bloomberg U.S. Aggregate Float Adjusted
Index
(reflects no deduction for fees, expenses,
or taxes)
-13.07
0.06
1.30
34

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 Manager
Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard’s Fixed Income Indexing Americas. He has managed the Fund since 2013.
Purchase and Sale of Fund Shares
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 and maintain a Fund account for Institutional Shares is $5 million. The minimum investment amount required to add to an existing Fund account is generally $1. If you are investing 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 gain. 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.
Payments to Financial Intermediaries
The Fund and its investment advisor do not pay financial intermediaries for sales of Fund shares.
35

Investing in Index Funds
What Is Indexing?
Indexing is an investment strategy for tracking the performance of a specified market benchmark, or “index.” An index is a group of securities whose overall performance is used as a standard to measure the investment performance of a particular market. There are many types of indexes. Some represent entire markets—such as the U.S. stock market or the U.S. bond market. Other indexes cover market segments—such as small-capitalization stocks or short-term bonds. One cannot invest directly in an index.
The index provider determines the securities to include in the index and the weighting of each security in the index. Under normal circumstances, the index provider will rebalance an index on a regular schedule. An index provider may carry out additional ad hoc index rebalances or delay or cancel a scheduled rebalance. Generally, the index provider does not provide any warranty, or accept any liability, with respect to the quality, accuracy, or completeness of either the target index or its related data. Errors made by the index provider may occur from time to time and may not be identified by the index provider for a period of time or at all. Vanguard does not provide any warranty or guarantee against such errors. Therefore, the gains, losses, or costs associated with the index provider’s errors 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 that make up its target index. Index funds attempt to mirror the performance of the target index, for better or worse. However, an index fund generally does not perform exactly like its target index. For example, index funds have operating expenses and transaction costs. Market indexes do not, and therefore they will usually have a slight performance advantage over funds that track them. The ability of an index fund to match its performance to that of its target index can also be impacted by, among other things, the timing and size of cash flows, asset valuation differences, and the size of the fund. Market disruptions could also have an adverse effect on a fund’s ability to adjust its exposure to the required levels in order to track the index. The risk that a fund may not track the performance of its target index may be heightened during times of increased market volatility or other unusual market conditions.
Index funds typically have the following characteristics:
• Variety of investments. Depending on a fund’s benchmark index, the fund may invest in the securities of a variety of companies, industries, and/or governments or government agencies.
• Relative performance consistency. Because they seek to track market benchmarks, index funds usually do not perform dramatically better or worse than their benchmarks.
• Low cost. Index funds are generally inexpensive to run compared with actively managed funds. They have low or no research costs and typically keep trading activity—and thus dealer markups and other transaction costs—to a minimum compared with actively managed funds.
36

More on the Funds
This prospectus describes the principal risks you would face as a Fund shareholder. It is important to keep in mind one of the main principles of investing: generally, the higher the risk of losing money, the higher the potential reward. The reverse, also, is generally true: the lower the risk, the lower the potential reward. As you consider an investment in any mutual fund, you should take into account your personal tolerance for fluctuations in the securities markets. Look for this  symbol throughout the prospectus. It is used to mark detailed information about the more significant risks that you would confront as a Fund shareholder. To highlight terms and concepts important to mutual fund investors, we have provided Plain Talk® explanations along the way. Reading the prospectus will help you decide whether a Fund is the right investment for you. We suggest that you keep this prospectus for future reference.
Share Class Overview
This prospectus offers the Funds' Institutional Shares, which are generally for investors who invest a minimum of $5 million. A separate prospectus offers the Funds’ Admiral™ Shares, which generally have an investment minimum of $3,000. In addition, each Fund issues ETF Shares (an exchange-traded class of shares), which are also offered through a separate prospectus.
All share classes offered by a Fund have the same investment objective, strategies, and policies. However, different share classes may have different expenses; as a result, their investment returns may differ.
Plain Talk About Costs of Investing
Costs are an important consideration in choosing a mutual fund. That is
because you, as a shareholder, pay a proportionate share of the costs of
operating a fund and any transaction costs incurred when the fund buys or
sells securities, including costs generated by shareholders of other share
classes offered by the fund. These costs can erode a substantial portion of
the gross income or the capital appreciation a fund achieves. Even
seemingly small differences in expenses can, over time, have a dramatic
effect on a fund’s performance.
The following sections explain the principal investment strategies and policies that each Fund uses in pursuit of its investment objective. The Funds' board of trustees, which oversees each Fund's management, may change investment strategies or policies in the interest of shareholders without a shareholder vote, unless those strategies or policies are designated as fundamental. Note that each Fund’s investment objective is not fundamental and may be changed
37

without a shareholder vote. However, each Fund’s policy of investing at least 80% of its assets in bonds that are included in its target index may be changed only upon 60 days’ notice to shareholders.
Market Exposure
Each Fund is subject to interest rate risk, which is the chance that bond prices will decline because of rising interest rates. Interest rate risk should be low for short-term bond funds, moderate for intermediate-term bond funds, and high for long-term bond funds.
Although fixed income securities (commonly referred to as bonds) are often thought to be less risky than stocks, there have been periods when bond prices have fallen significantly because of rising interest rates. For instance, prices of long-term bonds fell by almost 48% between December 1976 and September 1981.
To illustrate the relationship between bond prices and interest rates, the following table shows the effect of a 1% and a 2% change (both up and down) in interest rates on the values of three noncallable bonds (i.e., bonds that cannot be redeemed by the issuer) of different maturities, each with a face value of $1,000.
How Interest Rate Changes Affect the Value of a $1,000 Bond1
Type of Bond (Maturity)
After a 1%
Increase
After 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 an indication of future performance of the bond market as a whole or the Funds in particular.
38

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 interest
rates move in opposite directions? Let’s assume that you hold a bond
offering a 4% yield. A year later, interest rates are on the rise and bonds of
comparable quality and maturity are offered with a 5% yield. With
higher-yielding bonds available, you would have trouble selling your 4% bond
for 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 being
offered, you should be able to sell your 4% bond for more than you paid.
How mortgage-backed securities are different: In general, declining interest
rates will not lift the prices of mortgage-backed securities—such as those
guaranteed by the Government National Mortgage Association—as much as
the prices of comparable bonds. Why? Because when interest rates fall, the
bond market tends to discount the prices of mortgage-backed securities for
prepayment risk—the possibility that homeowners will refinance their
mortgages at lower rates and cause the bonds to be paid off prior to maturity.
In part to compensate for this prepayment possibility, mortgage-backed
securities tend to offer higher yields than other bonds of comparable credit
quality and maturity. In contrast, when interest rates rise, prepayments tend
to slow down, subjecting mortgage-backed securities to extension risk—the
possibility that homeowners will repay their mortgages at slower rates. This
will lengthen the duration or average life of mortgage-backed securities held
by a fund and delay the fund’s ability to reinvest proceeds at higher interest
rates, making the fund more sensitive to changes in interest rates.
Changes in interest rates can affect bond income as well as bond prices.
Each Fund is subject to income risk, which is the chance that the Fund's income will decline because of falling interest rates. A fund's income declines when interest rates fall because the fund then must invest new cash flow and cash from maturing bonds in lower-yielding bonds. Income risk is generally higher for short-term bond funds and lower for long-term bond funds.
39

Plain Talk About Bond Maturities
A bond is issued with a specific maturity date—the date when the issuer must
pay back the bond’s principal (face value). Bond maturities range from less
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 rates rise—but
also the higher the potential yield you could receive. Longer-term bonds are
generally more suitable for investors willing to take a greater risk of price
fluctuations to get higher and more stable interest income. Shorter-term bond
investors should be willing to accept lower yields and greater income
variability in return for less fluctuation in the value of their investment. The
stated 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 may
cause bonds to be repaid before their stated maturity dates.
Although falling interest rates tend to strengthen bond prices, they can cause other problems for bond fund investors—bond calls and prepayments.
Each Fund (other than Vanguard Mortgage-Backed Securities Index Fund) is subject to call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (redeem) securities with higher coupon rates or interest rates before their maturity dates. The Fund would then lose any price appreciation above the bond’s call price and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund’s income. Such redemptions and subsequent reinvestments would also increase the Fund’s portfolio turnover rate.
The indexes that Vanguard Treasury and Corporate Bond Index Funds seek to track include only a limited number of callable bonds. Thus, call risk for these Funds should be very low.
Vanguard Mortgage-Backed Securities Index Fund is subject to prepayment risk, which is the chance that during periods of falling interest rates, homeowners will refinance their mortgages before their maturity dates, resulting in prepayment of mortgage-backed securities held by the Fund. The Fund would then lose any price appreciation above the mortgage’s principal and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund’s income. Such prepayments and subsequent reinvestments would also increase the Fund's portfolio turnover rate. Prepayment risk is high for the Fund.
40

Vanguard Mortgage-Backed Securities Index Fund is subject to extension risk, which is the chance that during periods of rising interest rates, homeowners will repay their mortgages at slower rates. This will lengthen the duration or average life of mortgage-backed securities held by the Fund and delay the Fund's ability to reinvest proceeds at higher interest rates. Extension risk is high for the Fund.
Each Fund (other than the three Vanguard Treasury Index Funds) is subject to credit risk, which is the chance that a bond issuer will fail to pay interest or principal in a timely manner or that negative perceptions of the issuer’s ability to make such payments will cause the price of that bond to decline.
Plain Talk About Credit Quality
A bond’s credit quality rating is an assessment of the issuer’s ability to pay
interest on the bond and, ultimately, to repay the principal. The lower the
credit quality, the greater the perceived chance that the bond issuer will
default, or fail to meet its payment obligations. All things being equal, the
lower a bond’s credit quality, the higher its yield should be to compensate
investors for assuming additional risk. Mortgage-backed securities typically
have higher yields than comparable-quality corporate or government bonds
to make up for their higher prepayment risk.

Vanguard Mortgage-Backed Securities Index Fund has low credit risk. The three Treasury Index Funds invest primarily in U.S. Treasury securities and have high credit quality and low credit risk. The three Corporate Bond Index Funds are expected to have moderate credit risk as a result of their investments in investment-grade bonds. Investment-grade bonds are those rated BBB/Baa or higher by a credit rating agency, and therefore investment-grade bonds are a mixture of high-and medium-quality bonds.
Vanguard Short-Term Corporate Bond Index, Intermediate-Term Corporate Bond Index, Long-Term Corporate Bond Index, and Mortgage-Backed Securities Index Funds are subject to liquidity risk, which is the chance that a Fund may not be able to sell a security in a timely manner at a desired price.
Corporate bonds are traded among dealers and brokers that connect buyers with sellers. Liquidity in the corporate bond market may be challenged depending on overall economic conditions and credit tightening. There may be little trading in the secondary market for particular bonds and other debt securities, which may make them more difficult to value or sell.
41

To a limited extent, Corporate Bond Index Funds are subject to event risk, which is the chance that corporate fixed income securities held by these Funds may suffer a substantial decline in credit quality and market value because of a restructuring of the companies that issued the securities or because of other factors negatively affecting issuers.
Plain Talk About Types of Bonds
Bonds are issued (sold) by many sources: Corporations issue corporate
bonds; the federal government issues U.S. Treasury bonds; agencies of the
federal government issue agency bonds; financial institutions issue
asset-backed bonds; and mortgage holders issue “mortgage-backed”
pass-through certificates. Each issuer is responsible for paying back the
bond’s initial value as well as for making periodic interest payments. Many
bonds issued by government agencies and entities are neither guaranteed
nor insured by the U.S. government.
Market disruptions can adversely affect local and global markets as well as normal market conditions and operations. Any such disruptions could have an adverse impact on the value of a Fund's investments and Fund performance.
Security Selection
Index sampling strategy. Because it would be very expensive and inefficient to buy and sell all bonds held in its target index—which is an indexing strategy called “replication”—each Fund uses index “sampling” techniques to select securities. Using computer programs, each Fund’s advisor generally selects a representative sample of securities that approximates the full target index in terms of key risk factors and other characteristics. These factors include duration, cash flow, quality, and callability of the underlying bonds. In addition, each Fund keeps sector and subsector exposure within tight boundaries relative to its target index. Because the Funds do not hold all of the securities included in their target indexes, some of the securities (and issuers) that are held will likely be overweighted (or underweighted) compared with the target indexes. The maximum overweight (or underweight) is constrained at the issuer level with the goal of producing well-diversified credit exposure in the portfolio.
The components of the target indices of each Fund are reconstituted and rebalanced on a monthly basis. Each index rebalances as a float-adjusted market-weighted index, and bonds may enter or fall out of the index on a monthly basis. New securities are added to and removed from an index in connection with the month-end index rebalancing process.
42

Each Fund is subject to index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk is expected to be low for each Fund.
The following table shows the number of bonds held by each Fund, as well as the number of bonds in each Fund’s target index, as of August 31, 2023.
Vanguard Fund
Number of
Bonds in Fund
Number of Bonds
in Target Index
Vanguard Short-Term Treasury Index Fund
97
157
Vanguard Intermediate-Term Treasury
Index Fund
109
109
Vanguard Long-Term Treasury Index Fund
78
78
Vanguard Short-Term Corporate Bond
Index Fund
2,498
2,704
Vanguard Intermediate-Term Corporate
Bond Index Fund
2,085
2,090
Vanguard Long-Term Corporate Bond
Index Fund
2,794
2,885
Vanguard Mortgage-Backed Securities
Index Fund
1,1691
932
1 Issues are mortgage pools grouped by coupon.
Types of bonds. Each Fund seeks to track an index that is a subset of the Bloomberg U.S. Aggregate Float Adjusted Index (the Aggregate Index). The Aggregate Index measures the total universe of taxable fixed income securities in the United States—including government, corporate, and international dollar-denominated bonds, as well as mortgage-backed securities—all with maturities of at least 1 year. Taken together, the seven Funds cover approximately 97% of the Aggregate Index; the only sectors not covered are asset-backed bonds, bonds issued by foreign governments (unless guaranteed by the U.S. government), taxable state and municipal bonds, and commercial mortgage-backed securities.
43

The following grid shows, at a glance, the types of financial instruments that may be purchased by each Fund. An explanation of each type of financial instrument follows the grid.
 
Treasury Index
Funds
Corporate Bond
Index Funds
Mortgage-Backed
Securities
Index Fund
Corporate Debt Obligations
U.S. Government and Agency
Bonds
Mortgage-Backed Securities
Mortgage Dollar Rolls
Cash Equivalent Investments,
Including Repurchase Agreements
Futures, Options, and Other
Derivatives
International Dollar-Denominated
Bonds
• Corporate debt obligations—usually called bonds—represent loans by an investor to a corporation.
• U.S. government and agency bonds represent loans by investors to the U.S. Treasury or a wide variety of government agencies and instrumentalities. Securities issued by most U.S. government entities are neither guaranteed by the U.S. Treasury nor backed by the full faith and credit of the U.S. government. These entities include, among others, the Federal Home Loan Banks (FHLBs), the Federal National Mortgage Association (FNMA), and the Federal Home Loan Mortgage Corporation (FHLMC). Securities issued by the U.S. Treasury and a small number of U.S. government agencies, such as the Government National Mortgage Association (GNMA), are backed by the full faith and credit of the U.S. government. The market values of U.S. government and agency securities and U.S. Treasury securities are subject to fluctuation.
• Mortgage-backed securities represent partial ownership interest in pools of commercial or residential mortgage loans made by financial institutions to finance a borrower’s real estate purchase. These loans are packaged by private or governmental issuers for sale to investors. As the underlying mortgage loans are paid by borrowers, the investors receive payments of interest and principal. To be announced (TBA) securities represent an agreement to buy or sell mortgage-backed securities with agreed-upon characteristics for a fixed unit price, with settlement on a scheduled future date beyond the typical settlement period for most other securities.
44

• Mortgage dollar rolls are transactions in which a fund sells mortgage-backed securities to a dealer and simultaneously agrees to purchase similar securities in the future at a predetermined price. These transactions simulate an investment in mortgage-backed securities and have the potential to enhance a fund’s returns and reduce its administrative burdens, compared with holding mortgage-backed securities directly. These transactions may increase a fund’s portfolio turnover rate. Mortgage dollar rolls will be used only if consistent with a fund's investment objective and risk profile.
• Cash equivalent investments is a blanket term that describes a variety of short-term fixed income investments, including money market instruments, commercial paper, bank certificates of deposit, banker’s acceptances, and repurchase agreements. Repurchase agreements represent short-term (normally overnight) loans by a fund to banks or large securities dealers. Vanguard Treasury Index Funds and Vanguard Mortgage-Backed Securities Index Fund may invest only in repurchase agreements that are collateralized by U.S. Treasury or U.S. government agency securities. Repurchase agreements can carry several risks. For instance, if the seller is unable to repurchase the securities as promised, a fund may experience a loss when trying to sell the securities to another buyer. Also, if the seller becomes insolvent, a bankruptcy court may determine that the securities do not belong to a fund and order that the securities be used to pay off the seller’s debts. The Funds‘ advisor believes that these risks can be controlled through careful security selection and monitoring.
• Futures, options, and other derivatives are described in detail under Other Investment Policies and Risks.
• International dollar-denominated bonds are bonds denominated in U.S. dollars and issued by foreign governments and companies. To the extent that a Fund owns foreign bonds, it is subject to country risk, which is the chance that world events—such as political upheaval, financial troubles, or natural disasters—will adversely affect the value and/or liquidity of securities issued by companies in foreign countries. In addition, the prices of foreign bonds and the prices of U.S. bonds have, at times, moved in opposite directions. Because the bond’s value is designated in dollars rather than in the currency of the issuer’s country, the investor is not exposed to currency risk; rather, the issuer assumes that risk, usually to attract U.S. investors. Although currency movements do not affect the value of international dollar-denominated bonds directly, they could affect the value indirectly by adversely affecting the issuer’s ability (or the market’s perception of the issuer’s ability) to pay interest or repay principal.
45

Plain Talk About U.S. Government-Sponsored Enterprises
A variety of U.S. government-sponsored enterprises (GSEs), such as the
Federal Home Loan Mortgage Corporation (FHLMC), the Federal National
Mortgage Association (FNMA), and the Federal Home Loan Banks (FHLBs),
issue debt and mortgage-backed securities. Although GSEs may be chartered
or sponsored by acts of Congress, they are not funded by congressional
appropriations. In September of 2008, the U.S. Treasury placed FNMA and
FHLMC under conservatorship and appointed the Federal Housing Finance
Agency (FHFA) to manage their daily operations. In addition, the U.S. Treasury
entered into purchase agreements with FNMA and FHLMC to provide them
with capital in exchange for senior preferred stock. Generally, a GSE’s
securities are neither issued nor guaranteed by the U.S. Treasury and are not
backed by the full faith and credit of the U.S. government. In most cases, these
securities are supported only by the credit of the GSE, standing alone. In some
cases, a GSE’s securities may be supported by the ability of the GSE to
borrow from the U.S. Treasury or may be supported by the U.S. government in
some other way. Securities issued by the Government National Mortgage
Association (GNMA), however, are backed by the full faith and credit of the
U.S. government.
46

Other Investment Policies and Risks
Under normal circumstances, each Fund will invest at least 80% of its assets in bonds held in its target index. Up to 20% of each Fund’s assets may be used to purchase nonpublic, investment-grade securities, generally referred to as 144A securities, as well as smaller public issues or medium-term notes not included in the index because of the small size of the issue. The vast majority of these securities will have characteristics and risks similar to those in the target index. Subject to the same 20% limit, each Fund may also purchase other investments that are outside of its target index or may hold bonds that, when acquired, were included in the index but subsequently were removed.
Each Fund reserves the right to substitute a different index for the index it currently tracks if the current index is discontinued, if the Fund's agreement with the provider of its target index is terminated, or for any other reason determined in good faith by the Fund’s board of trustees. In any such instance, the substitute index would represent the same market segment as the current index.
Each Fund may invest in derivatives. In general, investments in derivatives may involve risks different from, and possibly greater than, those of investments directly in the underlying securities or assets.
Generally speaking, a derivative is a financial contract whose value is based on the value of a financial asset (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. Each Fund may invest in derivatives only if the expected risks and rewards of the derivatives are consistent with the investment objective, policies, strategies, and risks of the Fund as disclosed in this prospectus. In particular, derivatives will be used only when they may help the advisor to accomplish one or more of the following:
• Invest in eligible asset classes with greater efficiency and lower cost than is possible through direct investment.
• Add value when these instruments are attractively priced.
• Adjust sensitivity to changes in interest rates.
• Adjust overall credit risk of the portfolio.

The Funds' derivative investments may include fixed income futures contracts, fixed income options, interest rate swaps, total return swaps, credit default swaps, or other derivatives. Losses (or gains) involving futures contracts can sometimes be substantial—in part because a relatively small price movement in a futures contract may result in an immediate and substantial loss (or gain) for a fund. Similar risks exist for other types of derivatives.
47

Plain Talk About Derivatives
Derivatives can take many forms. Some forms of derivatives—such as
exchange-traded futures and options on securities, commodities, or
indexes—have been trading on regulated exchanges for decades. These
types of derivatives are standardized contracts that can easily be bought and
sold and whose market values are determined and published daily. On the
other hand, non-exchange-traded derivatives—such as certain swap
agreements—tend to be more specialized or complex and may be more
difficult to accurately value.
Each Fund may invest a small portion of its assets in fixed income futures, which are a type of derivative, and/or shares of exchange-traded funds (ETFs). These fixed income futures and ETFs typically provide returns similar to those of the bonds listed in the index, or in a subset of the index, the Fund seeks to track. A Fund may purchase futures or ETFs when doing so will reduce the Fund’s transaction costs, facilitate cash management, mitigate risk, or have the potential to add value because the instruments are favorably priced. Vanguard receives no additional revenue from Fund assets invested in ETF Shares of other Vanguard funds. Fund assets invested in ETF Shares of other Vanguard funds are excluded when allocating to the Fund its share of the costs of Vanguard operations.
Cash Management
Each Fund's daily cash balance may be invested in Vanguard Market Liquidity Fund and/or Vanguard Municipal Cash Management Fund (each, a CMT Fund), which are low-cost money market funds. When investing in a CMT Fund, each Fund bears its proportionate share of the expenses of the CMT Fund in which it invests. Vanguard receives no additional revenue from Fund assets invested in a CMT Fund.
Redemption Requests
Methods used to meet redemption requests. Under normal circumstances, each Fund typically expects to meet redemptions with positive cash flows. When this is not an option, each Fund seeks to maintain its risk exposure by selling a cross section of the Fund’s holdings to meet redemptions, while also factoring in transaction costs. Additionally, a Fund may work with larger clients to implement their redemptions in a manner that is least disruptive to the portfolio; see “Potentially disruptive redemptions” under Redeeming Shares in the Investing With Vanguard section.
48

Under certain circumstances, including under stressed market conditions, there are additional tools that each Fund may use in order to meet redemptions, including advancing the settlement of market trades with counterparties to match investor redemption payments or delaying settlement of an investor’s transaction to match trade settlement within regulatory requirements. A Fund may also suspend payment of redemption proceeds for up to seven days; see “Emergency circumstances” under Redeeming Shares in the Investing With Vanguard section. Additionally under these unusual circumstances, a Fund may borrow money (subject to certain regulatory conditions and if available under board-approved procedures) through an interfund lending facility; through a bank line-of-credit, including a joint committed credit facility; or through an uncommitted line-of-credit from Vanguard in order to meet redemption requests.
Potential redemption activity impacts. At times, a Fund may experience adverse effects when certain large shareholders, or multiple shareholders comprising significant ownership of the Fund or a share class of the Fund, redeem large amounts of shares of the Fund. Large redemptions may cause a Fund to sell portfolio securities at times when it would not otherwise do so. This may result in a Fund distributing capital gains or other taxable income to non-redeeming shareholders. Large redemptions may also increase a Fund's transaction costs. Redemption activity can occur for many reasons, including shareholder reactions to market movements or other events unrelated to Vanguard’s actions, or when Vanguard makes product changes that, for example, may result in a shareholder redeeming shares of a Fund to purchase shares of another similar fund or investment vehicle. When experiencing large redemptions, the Fund reserves the right to pay all or part of the redemption in-kind and/or delay payment of the redemption proceeds for up to seven calendar days; see “Potentially disruptive redemptions” under Redeeming Shares in the Investing With Vanguard section.
Temporary Investment Measures
Each Fund may temporarily depart from its normal investment policies and strategies 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's investment objective. For instance, the Fund may invest beyond its normal limits in derivatives or exchange-traded funds that are consistent with the Fund's investment objective when those instruments are more favorably priced or provide needed liquidity, as might be the case when the Fund receives large cash flows that it cannot prudently invest immediately.
49

Purchase and Transaction Fees
Vanguard Intermediate-Term and Long-Term Corporate Bond Index Funds charge fees of 0.25% and 1.00%, respectively, on all purchases of shares, including shares that you purchase by exchange from another Vanguard fund. In addition, Vanguard Short-Term and Intermediate-Term Corporate Bond Index Funds each reserve the right to impose a transaction fee on any purchase that, in the opinion of the advisor, would disrupt efficient management of the Fund. The advisor believes that it may be necessary to impose a transaction fee of 0.25% for Vanguard Short-Term Corporate Bond Index Fund and a transaction fee of 0.50% for Vanguard Intermediate-Term Corporate Bond Index Fund. The advisor may impose this transaction fee if an investor’s aggregate purchases into a Fund over a 12-month period exceed, or are expected to exceed, $100 million for Vanguard Short-Term Corporate Bond Index Fund or $50 million for Vanguard Intermediate-Term Corporate Bond Index Fund.


Unlike a sales charge or load paid to a broker or a fund management company, purchase and transaction fees are paid directly to the Fund to offset the costs of buying securities.


See Investing With Vanguard for more information about fees.
Frequent Trading or Market-Timing
Background. Some investors try to profit from strategies involving frequent trading of mutual fund shares, such as market-timing. For funds holding foreign securities, investors may try to take advantage of an anticipated difference between the price of the fund’s shares and price movements in overseas markets, a practice also known as time-zone arbitrage. Investors also may try to engage in frequent trading of funds holding investments such as small-cap stocks and high-yield bonds. As money is shifted into and out of a fund by a shareholder engaging in frequent trading, the fund incurs costs for buying and selling securities, resulting in increased brokerage and administrative costs. These costs are borne by all fund shareholders, including the long-term investors who do not generate the costs. In addition, frequent trading may interfere with an advisor’s ability to efficiently manage the fund.
Policies to address frequent trading. The Vanguard funds (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund) do not knowingly accommodate frequent trading. The board of trustees of each Vanguard fund (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund) has adopted policies and procedures reasonably designed to detect and discourage frequent trading and, in some
50

cases, to compensate the fund for the costs associated with it. These policies and procedures do not apply to ETF Shares because frequent trading in ETF Shares generally does not disrupt portfolio management or otherwise harm fund shareholders. Although there is no assurance that Vanguard will be able to detect or prevent frequent trading or market-timing in all circumstances, the following policies have been adopted to address these issues:
• Each Vanguard fund reserves the right to reject any purchase request—including exchanges from other Vanguard funds—without notice and regardless of size. For example, a purchase request could be rejected because the investor has a history of frequent trading or if Vanguard determines that such purchase may negatively affect a fund’s operation or performance.
• Each Vanguard fund (other than money market funds and short-term bond funds, but including Vanguard Short-Term Inflation-Protected Securities Index Fund) generally prohibits, except as otherwise noted in the Investing With Vanguard section, an investor’s purchases or exchanges into a fund account for 30 calendar days after the investor has redeemed or exchanged out of that fund account.
• Certain Vanguard funds charge shareholders purchase and/or redemption fees on transactions.
See the Investing With Vanguard section of this prospectus for further details on Vanguard’s transaction policies.
Each Vanguard fund (other than retail and government money market funds), in determining its net asset value, will use fair-value pricing when appropriate, as described in the Share Price section. Fair-value pricing may reduce or eliminate the profitability of certain frequent-trading strategies.
Do not invest with Vanguard if you are a market-timer.
A precautionary note to investment companies: Each Fund's shares are issued by registered investment companies, and therefore the acquisition of such shares by other investment companies and private funds is subject to the restrictions of Section 12(d)(1) of the Investment Company Act of 1940 (the 1940 Act). SEC Rule 12d1-4 under the 1940 Act permits registered investment companies to invest in other registered investment companies beyond the limits in Section 12(d)(1), subject to certain conditions, including that funds with different investment advisors must enter into a fund of funds investment agreement.
51

Turnover Rate
Although the Funds generally seek to invest for the long term, each Fund may sell securities regardless of how long they have been held. Generally, an index fund sells securities in response to redemption requests from shareholders of conventional (i.e., not exchange-traded) shares or to changes in the composition of its target index or in an effort to manage the fund’s duration. The Financial Highlights section of this prospectus shows historical turnover rates for the Funds. A turnover rate of 100%, for example, would mean that a Fund had sold and replaced securities valued at 100% of its net assets within a one-year period. Shorter-term bonds will mature or be sold—and need to be replaced—more frequently than longer-term bonds. As a result, shorter-term bond funds tend to have higher turnover rates than longer-term bond funds. In general, the greater the turnover rate, the greater the impact transaction costs will have on a fund’s return. Also, funds with high turnover rates may be more likely to generate capital gains, including short-term capital gains, that must be distributed to shareholders and will be taxable to shareholders investing through a taxable account.
The Funds and Vanguard
Each Fund is a member of The Vanguard Group, Inc. (Vanguard), a family of over 200 funds. All of the funds that are members of Vanguard (other than funds of funds) share in the expenses associated with administrative services and business operations, 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 distribution fees, each fund (other than a fund of funds) or each share class of a fund (in the case of a fund with multiple share classes) pays its allocated share of the Vanguard funds’ marketing costs.
Plain Talk About Vanguard’s Unique Corporate Structure
Vanguard is owned jointly by the funds it oversees and thus indirectly by the
shareholders in those funds. Most other mutual funds are operated by
management companies that are owned by third parties—either public or
private stockholders—and not by the funds they serve.
52

Investment Advisor
The Vanguard Group, Inc., P.O. Box 2600, Valley Forge, PA 19482, which began operations in 1975, serves as advisor to the Funds through its Fixed Income Group. As of August 31, 2023, Vanguard served as advisor for approximately $6.8 trillion in assets. Vanguard provides investment advisory services to the Funds pursuant to the Funds’ Service Agreement and subject to the supervision and oversight of the trustees and officers of the Funds.
For the fiscal year ended August 31, 2023, the advisory expenses for each Fund represented an effective annual rate of less than 0.01% of the Fund’s average net assets.
Under the terms of an SEC exemption, the Funds' board of trustees may, without prior approval from shareholders, change the terms of an advisory agreement with a third-party investment advisor or hire a new third-party investment advisor—either as a replacement for an existing advisor or as an additional advisor. Any significant change in a Fund's advisory arrangements will be communicated to shareholders in writing. As the Funds' sponsor and overall manager, Vanguard may provide investment advisory services to a Fund at any time. Vanguard may also recommend to the board of trustees that an advisor be hired, terminated, or replaced or that the terms of an existing advisory agreement be revised. The Funds have filed an application seeking a similar SEC exemption with respect to investment advisors that are wholly owned subsidiaries of Vanguard. If the exemption is granted, the Funds may rely on the new SEC relief.
For a discussion of why the board of trustees approved each Fund's investment advisory arrangement, see the most recent annual report to shareholders covering the fiscal year ended August 31.
The manager primarily responsible for the day-to-day management of the Funds is:
Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard’s Fixed Income Indexing Americas. He has been with Vanguard since 1998; has worked in investment management since 1999; has managed investment portfolios since 2005; has managed Vanguard Short-Term, Intermediate-Term, and Long-Term Corporate Bond Index Funds since their inceptions in 2009; and has managed Vanguard Short-Term, Intermediate-Term, and Long-Term Treasury Index Funds and managed Vanguard Mortgage-Backed Securities Index Fund since 2013. Education: B.S., Ohio Northern University; M.B.A., Lehigh University.
53

The Funds' Statement of Additional Information provides information about the portfolio manager’s compensation, other accounts under management, and ownership of shares of the Funds.
Dividends, Capital Gains, and Taxes
Fund Distributions
Each Fund distributes to shareholders virtually all of its net income (interest less expenses) as well as any net short-term or long-term capital gains realized from the sale of its holdings. From time to time, each Fund may also make distributions that are treated as a return of capital. Income dividends generally are declared and distributed monthly; capital gains distributions, if any, generally occur annually in December. In addition, each Fund may occasionally make a supplemental distribution at some other time during the year.
You can receive distributions of income or capital gains in cash, or you can have them automatically reinvested in more shares of the Fund. However, if you are investing through an employer-sponsored retirement or savings plan, your distributions will be automatically reinvested in additional Fund shares.
Plain Talk About Distributions
As a shareholder, you are entitled to your portion of a fund’s income from
interest as well as capital gains from the fund’s sale of investments. Income
consists of interest the fund earns from its money market and bond
investments. Capital gains are realized whenever the fund sells securities for
higher prices than it paid for them. These capital gains are either short-term
or long-term, depending on whether the fund held the securities for one year
or less or for more than one year.
Basic Tax Points
Investors in taxable accounts should be aware of the following basic federal income tax points:
• Distributions are taxable to you whether or not you reinvest these amounts in additional Fund shares.
• Distributions declared in December—if paid to you by the end of January—are taxable as if received in December.
• Any income dividend distribution or short-term capital gains distribution that you receive is taxable to you as ordinary income.
54

• Any distribution of net long-term capital gains is taxable to you as long-term capital gains, no matter how long you have owned shares in the Fund.
• Capital gains distributions may vary considerably from year to year as a result of the Funds' normal investment activities and cash flows.
• Your cost basis in the Fund will be decreased by the amount of any return of capital that you receive. This, in turn, will affect the amount of any capital gain or loss that you realize when selling your Fund shares.
• Return of capital distributions generally are not taxable to you until your cost basis has been reduced to zero. If your cost basis is at zero, return of capital distributions will be treated as capital gains.
• A sale or exchange of Fund shares is a taxable event. This means that you may have 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 nontaxable event. By contrast, an exchange between classes of shares of different funds is a taxable event.
• Vanguard (or your intermediary) will send you a statement each year showing the tax status of all of your distributions.
Individuals, trusts, and estates whose income exceeds certain threshold amounts are subject to a 3.8% Medicare contribution tax on “net investment income.” Net investment income takes into account distributions paid by the Fund and capital gains from any sale or exchange of Fund shares.
Income dividends and capital gains distributions that you receive, as well as your gains or losses from any sale or exchange of Fund shares, may be subject to state and local income taxes. Depending on your state’s rules, however, any dividends attributable to interest earned on direct obligations of the U.S. government may be exempt from state and local taxes. Vanguard will notify you each year how much, if any, of your dividends may qualify for this exemption.
This prospectus provides general tax information only. 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. Please consult your tax advisor for detailed information about any tax consequences for you.
55

General Information
Backup withholding. By law, Vanguard must withhold 24% of any taxable distributions 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 account if the IRS instructs us to do so.
Foreign investors. Vanguard funds offered for sale in the United States (Vanguard U.S. funds), including the Funds offered in this prospectus, are not widely available outside the United States. Non-U.S. investors should be aware that U.S. withholding and estate taxes and certain U.S. tax reporting requirements may apply to any investments in Vanguard U.S. funds. Foreign investors should visit the non-U.S. investors page on our website at vanguard.com for information on Vanguard’s non-U.S. products.
Invalid addresses. If an income dividend distribution or capital gains distribution check mailed to your address of record is returned as undeliverable, Vanguard will automatically reinvest the distribution and all future distributions until you provide us with a valid mailing address. Reinvestments will receive the net asset value calculated on the date of the reinvestment.
Share Price
Share price, also known as net asset value (NAV), is calculated as of the close of regular 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 is unavailable at the close of the trading day, NAVs will be calculated as of the close of regular trading on the Nasdaq (or another alternate exchange if the Nasdaq is unavailable, as determined at Vanguard’s discretion), generally 4 p.m., Eastern time. Each share class has its own NAV, which is computed by dividing the total assets, minus liabilities, allocated to the share class by the number of Fund shares outstanding for that class. On U.S. holidays or other days when the NYSE is closed, the NAV is not calculated, and the Funds do not sell or redeem shares. However, on those days the value of a Fund’s assets may be affected to the extent that the Fund holds securities that change in value on those days (such as foreign securities that trade on foreign markets that are open).
56

Debt securities held by a Vanguard fund are valued based on information furnished by an independent pricing service or market quotations. When a fund determines that pricing-service information or market quotations either are not readily available or do not accurately reflect the value of a security, the security is priced at its fair value (the amount that the owner might reasonably expect to receive upon the current sale of the security).
The values of any foreign securities held by a fund are converted into U.S. dollars using an exchange rate obtained from an independent third party as of the close of regular trading on the NYSE. The values of any mutual fund shares, including institutional money market fund shares, held by a fund are based on the NAVs of the shares. The values of any ETF shares or closed-end fund shares held by a fund are based on the market value of the shares.
A fund also may use fair-value pricing on bond market holidays when the fund is open for business (such as Columbus Day and Veterans Day). Fair-value prices are determined by Vanguard according to procedures adopted by the board of trustees. When fair-value pricing is employed, the prices of securities used by a fund to calculate the NAV may differ from quoted or published prices for the same securities.
Each Fund has authorized certain financial intermediaries and their designees, and may, from time to time, authorize certain funds of funds for which Vanguard serves as the investment advisor (Vanguard Funds of Funds), to accept orders to buy or sell fund shares on their behalf. The Fund will be deemed to receive an order when accepted by the financial intermediary, its designee, or one of the Vanguard Funds of Funds, and the order will receive the NAV next computed by the Fund after such acceptance.
Vanguard fund share prices are published daily on our website at vanguard.com/prices.
57

Financial Highlights
Financial highlights information is intended to help you understand a fund’s performance for the past five years (or, if shorter, its period of operations). Certain information reflects financial results for a single fund share. Total return represents the rate that an investor would have earned or lost each period on an investment in a fund or share class (assuming reinvestment of all distributions). This information has been obtained from the financial statements audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, whose report, along with fund financial statements, is included in a fund’s most recent annual report to shareholders. You may obtain a free copy of a fund’s latest annual or semiannual report, which is available upon request.
Vanguard Short-Term Treasury Index Fund Institutional Shares
For a Share Outstanding Throughout Each Period
Year Ended August 31,
2023
2022
2021
2020
2019
Net Asset Value, Beginning of Period
$24.50
$25.77
$26.02
$25.57
$25.06
Investment Operations
Net Investment Income1
.680
.145
.120
.421
.598
Net Realized and Unrealized Gain (Loss) on Investments
(.389)
(1.191)
(.092)
.445
.490
Total from Investment Operations
.291
(1.046)
.028
.866
1.088
Distributions
Dividends from Net Investment Income
(.651)
(.145)
(.122)
(.416)
(.578)
Distributions from Realized Capital Gains
(.079)
(.156)
Total Distributions
(.651)
(.224)
(.278)
(.416)
(.578)
Net Asset Value, End of Period
$24.14
$24.50
$25.77
$26.02
$25.57
Total Return
1.21%
-4.08%
0.11%
3.42%
4.40%
Ratios/Supplemental Data
 
 
 
 
 
Net Assets, End of Period (Millions)
$1,586
$1,092
$1,138
$1,104
$974
Ratio of Total Expenses to Average Net Assets
0.05%2
0.05%2
0.05%
0.05%
0.05%
Ratio of Net Investment Income to Average Net Assets
2.80%
0.58%
0.47%
1.63%
2.37%
Portfolio Turnover Rate3
81%
59%
66%
67%
55%
 
 
 
 
 
 
 
 
1
Calculated based on average shares outstanding.
2
The ratio of expenses to average net assets for the period net of reduction from custody fee
offset arrangements was 0.05%.
3
Excludes the value of portfolio securities received or delivered as a result of in-kind purchases
or redemptions of the fund’s capital shares, including ETF Creation Units.
58

Vanguard Intermediate-Term Treasury Index Fund Institutional Shares
For a Share Outstanding Throughout Each Period
Year Ended August 31,
2023
2022
2021
2020
2019
Net Asset Value, Beginning of Period
$25.26
$28.60
$29.51
$28.15
$26.23
Investment Operations
Net Investment Income1
.615
.355
.337
.527
.634
Net Realized and Unrealized Gain (Loss) on Investments
(.935)
(3.195)
(.709)
1.355
1.908
Total from Investment Operations
(.320)
(2.840)
(.372)
1.882
2.542
Distributions
Dividends from Net Investment Income
(.600)
(.346)
(.334)
(.522)
(.622)
Distributions from Realized Capital Gains
(.154)
(.204)
Total Distributions
(.600)
(.500)
(.538)
(.522)
(.622)
Net Asset Value, End of Period
$24.34
$25.26
$28.60
$29.51
$28.15
Total Return
-1.27%
-10.03%
-1.26%
6.76%
9.83%
Ratios/Supplemental Data
 
 
 
 
 
Net Assets, End of Period (Millions)
$2,203
$1,700
$1,725
$1,558
$1,183
Ratio of Total Expenses to Average Net Assets
0.05%2
0.05%2
0.05%
0.05%
0.05%
Ratio of Net Investment Income to Average Net Assets
2.49%
1.32%
1.17%
1.83%
2.36%
Portfolio Turnover Rate3
36%
36%
33%
28%
29%
 
 
 
 
 
 
 
 
1
Calculated based on average shares outstanding.
2
The ratio of expenses to average net assets for the period net of reduction from custody fee
offset arrangements was 0.05%.
3
Excludes the value of portfolio securities received or delivered as a result of in-kind purchases
or redemptions of the fund’s capital shares, including ETF Creation Units.
59

Vanguard Long-Term Treasury Index Fund Institutional Shares
For a Share Outstanding Throughout Each Period
Year Ended August 31,
2023
2022
2021
2020
2019
Net Asset Value, Beginning of Period
$29.16
$38.52
$42.19
$38.43
$31.66
Investment Operations
Net Investment Income1
.847
.727
.699
.822
.902
Net Realized and Unrealized Gain (Loss) on Investments
(3.641)
(9.376)
(3.554)
3.748
6.753
Total from Investment Operations
(2.794)
(8.649)
(2.855)
4.570
7.655
Distributions
Dividends from Net Investment Income
(.826)
(.711)
(.691)
(.810)
(.885)
Distributions from Realized Capital Gains
(.124)
Total Distributions
(.826)
(.711)
(.815)
(.810)
(.885)
Net Asset Value, End of Period
$25.54
$29.16
$38.52
$42.19
$38.43
Total Return
-9.68%
-22.69%
-6.77%
12.03%
24.71%
Ratios/Supplemental Data
 
 
 
 
 
Net Assets, End of Period (Millions)
$3,026
$2,586
$2,038
$1,234
$1,054
Ratio of Total Expenses to Average Net Assets
0.05%2
0.05%2
0.05%
0.05%
0.05%
Ratio of Net Investment Income to Average Net Assets
3.14%
2.15%
1.82%
2.06%
2.75%
Portfolio Turnover Rate3
20%
19%
22%
29%
16%
 
 
 
 
 
 
 
 
1
Calculated based on average shares outstanding.
2
The ratio of expenses to average net assets for the period net of reduction from custody fee
offset arrangements was 0.05%.
3
Excludes the value of portfolio securities received or delivered as a result of in-kind purchases
or redemptions of the fund’s capital shares, including ETF Creation Units.
60

Vanguard Short-Term Corporate Bond Index Fund Institutional Shares
For a Share Outstanding Throughout Each Period
Year Ended August 31,
2023
2022
2021
2020
2019
Net Asset Value, Beginning of Period
$25.34
$27.53
$27.61
$27.00
$26.06
Investment Operations
Net Investment Income1
.702
.436
.473
.713
.768
Net Realized and Unrealized Gain (Loss) on Investments
(.149)
(2.131)
(.080)
.604
.939
Total from Investment Operations
.553
(1.695)
.393
1.317
1.707
Distributions
Dividends from Net Investment Income
(.703)
(.434)
(.473)
(.707)
(.767)
Distributions from Realized Capital Gains
(.061)
Total Distributions
(.703)
(.495)
(.473)
(.707)
(.767)
Net Asset Value, End of Period
$25.19
$25.34
$27.53
$27.61
$27.00
Total Return
2.22%
-6.21%
1.44%
4.96%
6.66%
Ratios/Supplemental Data
 
 
 
 
 
Net Assets, End of Period (Millions)
$2,444
$2,239
$2,258
$1,661
$1,633
Ratio of Total Expenses to Average Net Assets
0.05%2
0.05%2
0.05%
0.05%
0.05%
Ratio of Net Investment Income to Average Net Assets
2.79%
1.65%
1.72%
2.63%
2.92%
Portfolio Turnover Rate3
63%
50%
42%
56%
51%
 
 
 
 
 
 
 
 
1
Calculated based on average shares outstanding.
2
The ratio of expenses to average net assets for the period net of reduction from custody fee
offset arrangements was 0.05%.
3
Excludes the value of portfolio securities received or delivered as a result of in-kind purchases
or redemptions of the fund’s capital shares, including ETF Creation Units.
61

Vanguard Intermediate-Term Corporate Bond Index Fund Institutional Shares
For a Share Outstanding Throughout Each Period
Year Ended August 31,
2023
2022
2021
2020
2019
Net Asset Value, Beginning of Period
$26.56
$31.82
$31.95
$30.53
$27.94
Investment Operations
Net Investment Income1
.934
.720
.720
.940
1.044
Net Realized and Unrealized Gain (Loss) on Investments
(.538)
(5.061)
(.070)
1.394
2.584
Total from Investment Operations
.396
(4.341)
.650
2.334
3.628
Distributions
Dividends from Net Investment Income
(.936)
(.721)
(.714)
(.914)
(1.038)
Distributions from Realized Capital Gains
(.198)
(.066)
Total Distributions
(.936)
(.919)
(.780)
(.914)
(1.038)
Net Asset Value, End of Period
$26.02
$26.56
$31.82
$31.95
$30.53
Total Return2
1.54%
-13.87%
2.07%
7.81%
13.30%
Ratios/Supplemental Data
 
 
 
 
 
Net Assets, End of Period (Millions)
$298
$338
$443
$357
$406
Ratio of Total Expenses to Average Net Assets
0.05%3
0.05%3
0.05%
0.05%
0.05%
Ratio of Net Investment Income to Average Net Assets
3.57%
2.46%
2.27%
3.07%
3.65%
Portfolio Turnover Rate4
76%
58%
53%
72%
59%
 
 
 
 
 
 
 
 
1
Calculated based on average shares outstanding.
2
Total returns do not include transaction fees that may have applied in the periods shown.
Fund prospectuses provide information about any applicable transaction fees.
3
The ratio of expenses to average net assets for the period net of reduction from custody fee
offset arrangements was 0.05%.
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, including ETF Creation Units.
62

Vanguard Long-Term Corporate Bond Index Fund Institutional Shares
For a Share Outstanding Throughout Each Period
Year Ended August 31,
2023
2022
2021
2020
2019
Net Asset Value, Beginning of Period
$26.76
$36.02
$35.59
$34.18
$29.36
Investment Operations
Net Investment Income1
1.227
1.092
1.095
1.250
1.314
Net Realized and Unrealized Gain (Loss) on Investments2
(1.575)
(9.264)
.425
1.387
4.812
Total from Investment Operations
(.348)
(8.172)
1.520
2.637
6.126
Distributions
Dividends from Net Investment Income
(1.202)
(1.088)
(1.090)
(1.227)
(1.306)
Distributions from Realized Capital Gains
Total Distributions
(1.202)
(1.088)
(1.090)
(1.227)
(1.306)
Net Asset Value, End of Period
$25.21
$26.76
$36.02
$35.59
$34.18
Total Return3
-1.28%
-23.05%
4.37%
7.91%
21.58%
Ratios/Supplemental Data
 
 
 
 
 
Net Assets, End of Period (Millions)
$414
$264
$340
$268
$541
Ratio of Total Expenses to Average Net Assets
0.05%4
0.05%4
0.05%
0.05%
0.05%
Ratio of Net Investment Income to Average Net Assets
4.78%
3.46%
3.09%
3.68%
4.36%
Portfolio Turnover Rate5