485BPOS
Vanguard Variable Insurance Funds
Mid-Cap Index Portfolio
April 28, 2023
Prospectus

This prospectus contains financial data for the Portfolio through the fiscal year ended December 31, 2022.

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

Portfolio Summary
Investment Objective
The Portfolio seeks to track the performance of a benchmark index that measures the investment return of mid-capitalization stocks.
Fees and Expenses
The following table describes the fees and expenses you may pay if you buy, hold, and sell shares of the Portfolio. The expenses shown in the table and in the example that follows do not reflect additional fees and expenses associated with the annuity or life insurance program through which you invest. If those additional fees and expenses were included, overall expenses would be higher.
Annual Portfolio Operating Expenses
(Expenses that you pay each year as a percentage of the value of your investment)
 
Management Fees
0.16%
12b-1 Distribution Fee
None
Other Expenses
0.01%
Total Annual Portfolio Operating Expenses
0.17%
Example
The following example is intended to help you compare the cost of investing in the Portfolio 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 Portfolio's shares. This example assumes that the Portfolio provides a return of 5% each year and that total annual portfolio 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
$17
$55
$96
$217
Portfolio Turnover
The Portfolio 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. These costs, which are not reflected in annual portfolio operating expenses or in the previous expense example, reduce the Portfolio's performance. During the most recent fiscal year, the Portfolio's turnover rate was 16% of the average value of its portfolio.
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Principal Investment Strategies
Vanguard Variable Insurance Funds Mid-Cap Index Portfolio (the Mid-Cap Index Portfolio) employs an indexing investment approach designed to track the performance of the CRSP US Mid Cap Index, a broadly diversified index of stocks of mid-size U.S. companies. The Portfolio attempts to replicate the target index by investing all, or substantially all, of its assets in the stocks that make up the Index, holding each stock in approximately the same proportion as its weighting in the Index.
Principal Risks
An investment in the Portfolio could lose money over short or long periods of time. You should expect the Portfolio's share price and total return to fluctuate within a wide range. The Portfolio is subject to the following risks, which could affect the Portfolio's performance:
• Stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Portfolio’s target index tracks a subset of the U.S. stock market, which could cause the Portfolio to perform differently from the overall stock market. In addition, the Portfolio’s target index may, at times, become focused in stocks of a particular market sector, which would subject the Portfolio to proportionately higher exposure to the risks of that sector.
• Investment style risk, which is the chance that returns from mid-capitalization stocks will trail returns from the overall stock market. Historically, mid-cap stocks have been more volatile in price than the large-cap stocks that dominate the overall market, and they often perform quite differently. The stock prices of mid-size companies tend to experience greater volatility because, among other things, these companies tend to be more sensitive to changing economic conditions.
• Index replicating risk, which is the chance that the Portfolio may be prevented from holding one or more securities in the same proportion as in its target index.
An investment in the Portfolio 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 Portfolio. The bar chart shows how the performance of the Portfolio has varied from one calendar year to another over the periods shown. The table shows how the average annual total returns of the Portfolio compare with those of its target index and other comparative indexes, which have
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investment characteristics similar to those of the Portfolio. The Spliced Mid Cap Index reflects the performance of the MSCI US Mid Cap 450 Index through January 30, 2013, and the CRSP US Mid Cap Index thereafter. The Portfolio’s returns are net of its expenses but do not reflect additional fees and expenses that are deducted by the annuity or life insurance program through which you invest. If such fees and expenses were included in the calculation of the Portfolio’s returns, the returns would be lower. Keep in mind that the Portfolio's past performance does not indicate how the Portfolio will perform in the future. Updated performance information is available on our website for Financial Advisors at advisors.vanguard.com or by calling Vanguard toll-free at 800-522-5555.
Annual Total Returns — Mid-Cap Index Portfolio
During the periods shown in the bar chart, the highest and lowest returns for a calendar quarter were:
 
Total Return
Quarter
Highest
24.95%
June 30, 2020
Lowest
-25.82%
March 31, 2020
Average Annual Total Returns for Periods Ended December 31, 2022
 
1 Year
5 Years
10 Years
Mid-Cap Index Portfolio
-18.82%
7.18%
10.95%
Spliced Mid Cap Index
(reflects no deduction for fees, expenses, or taxes)
-18.68%
7.34%
11.13%
CRSP US Mid Cap Index
(reflects no deduction for fees, expenses, or taxes)
-18.68
7.34
11.13
Dow Jones U.S. Total Stock Market Float Adjusted Index
(reflects no deduction for fees, expenses, or taxes)
-19.53
8.65
12.03
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Investment Advisor
The Vanguard Group, Inc. (Vanguard)
Portfolio Managers
Donald M. Butler, CFA, Principal of Vanguard. He has managed the Portfolio since its inception in 1999 (co-managed since 2016).
Awais Khan, CFA, Portfolio Manager at Vanguard. He has co-managed the Portfolio since 2021.
Tax Information
The Portfolio normally distributes its net investment income and net realized capital gains, if any, to its shareholders, which are the insurance company separate accounts that sponsor your variable annuity or variable life insurance contract. The tax consequences to you of your investment in the Portfolio depend on the provisions of the annuity or life insurance contract through which you invest. For more information on taxes, please refer to the prospectus of the annuity or life insurance contract through which Portfolio shares are offered.
Payments to Financial Intermediaries
The Portfolio and its investment advisor do not pay financial intermediaries for sales of Portfolio shares.
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More on the Portfolio
This prospectus describes the principal risks you would face as an investor in this Portfolio. 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 Portfolio investor. 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 the Portfolio is the right investment for you. We suggest that you keep this prospectus for future reference.
A Note About Vanguard Variable Insurance Funds
The Mid-Cap Index Portfolio of Vanguard Variable Insurance Funds is a mutual fund used solely as an investment option for annuity or life insurance contracts offered by insurance companies. This means that you cannot purchase shares of the Portfolio directly, but only through a contract offered by an insurance company.
The Mid-Cap Index Portfolio is separate from other Vanguard mutual funds, even when the Portfolio and a fund have the same investment objective and advisor. The Portfolio’s investment performance will differ from the performance of other Vanguard funds because of differences in the securities held and because of administrative and insurance costs associated with the annuity or life insurance program through which you invest.
Plain Talk About Costs of Investing
Costs are an important consideration in choosing a mutual fund. That is
because you, as a contract owner, pay a proportionate share of the costs of
operating a fund and any transaction costs incurred when the fund buys or
sells securities. 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 the Portfolio uses in pursuit of its investment objective. The board of trustees of Vanguard Variable Insurance Funds (the Board), which oversees the Portfolio's management, may change investment strategies or policies in the
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interest of shareholders without a shareholder vote, unless those strategies or policies are designated as fundamental. Under normal circumstances, the Portfolio will invest at least 80% of its assets in the stocks that make up its target index. The Portfolio may change its 80% policy only upon 60 days‘ notice to shareholders.
Market Exposure
The Portfolio invests mainly in common stocks of U.S. companies.
The Portfolio is subject to stock market risk, which is the chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices. The Portfolio's target index tracks a subset of the U.S. stock market, which could cause the Portfolio to perform differently from the overall stock market. In addition, the Portfolio's target index may, at times, become focused in stocks of a particular market sector, which would subject the Portfolio to proportionately higher exposure to the risks of that sector.
Stocks of publicly traded companies are often classified according to market capitalization, which is the market value of a company’s outstanding shares. These classifications typically include small-cap, mid-cap, and large-cap. It is important to understand that there are no “official” definitions of small-, mid-, and large-cap, even among Vanguard fund advisors, and that market capitalization ranges can change over time. The asset-weighted median market capitalization of the Portfolio's stock holdings as of December 31, 2022, was $23.2 billion.
Stock funds can also be categorized according to whether the stocks they hold are value or growth stocks or a blend of both. The Mid-Cap Index Portfolio generally fits into the mid-cap blend category.
The Portfolio is subject to investment style risk, which is the chance that returns from mid-capitalization stocks will trail returns from the overall stock market. Historically, mid-cap stocks have been more volatile in price than the large-cap-stocks that dominate the overall market, and they often perform quite differently. The stock prices of mid-size companies tend to experience greater volatility because, among other things, these companies tend to be more sensitive to changing economic conditions.
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 the Portfolio's investments and Portfolio performance.
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Security Selection
The Portfolio is a stock index fund that seeks to track the performance of a benchmark index that measures the investment return of mid-capitalization stocks. The Portfolio employs an indexing investment approach designed to track the performance of the CRSP US Mid Cap Index, a broadly diversified index of stocks of mid-size U.S. companies. In seeking to replicate the Index’s performance, the Portfolio intends to hold each of the stocks in the Index in approximately the same proportion as its weighting in the Index. For example, if 3% of the CRSP US Mid Cap Index were made up of the stock of a specific company, the Portfolio would invest approximately 3% of its assets in that company. The actual stocks that make up the Index are chosen by CRSP.
The Portfolio is subject to Index replicating risk, which is the chance that the Portfolio may be prevented from holding one or more securities in the same proportion as in its target index.
The ability of the advisor to purchase or dispose of certain Portfolio investments is or may be restricted or impaired because of limitations imposed by law, regulation, or by certain regulators or issuers. As a result, the advisor may be required to limit purchases or sell existing investments. If the Portfolio is required to limit its investment in a particular issuer, then the Portfolio may seek to obtain regulatory relief or ownership waivers. Other options the Portfolio may pursue include seeking to obtain economic exposure to that issuer through alternative means, such as through a derivative or through investment in a wholly owned subsidiary, both of which may be more costly than owning securities of the issuer directly. Ownership restrictions and limitations could result in unanticipated tax consequences to the Portfolio that may affect the amount, timing, and character of distributions to shareholders. See Other Investment Policies and Risks for further information related to derivatives.
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Other Investment Policies and Risks
The Portfolio reserves the right to substitute a different index for the index it currently tracks if the current index is discontinued, if the Portfolio's agreement with the sponsor of its target index is terminated, or for any other reason determined in good faith by the Board. In any such instance, the substitute index would represent the same market segment as the current index.
The Portfolio may invest in foreign securities to the extent necessary to carry out its investment strategy of holding all, or substantially all, of the stocks that make up the index it tracks. It is not expected that the Portfolio will invest more than 5% of its assets in foreign securities.
To track its target index as closely as possible, the Portfolio attempts to remain fully invested in stocks. To help stay fully invested and to reduce transaction costs, the Portfolio may invest, to a limited extent, in derivatives, including equity futures. The Portfolio may also use derivatives such as total return swaps to obtain exposure to a stock, a basket of stocks, or an index. 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. Investments in derivatives may subject the Portfolio to risks different from, and possibly greater than, those of investments directly in the underlying securities or assets. The Portfolio will not use derivatives for speculation or for the purpose of leveraging (magnifying) investment returns.
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Cash Management
The Portfolio'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, the Portfolio bears its proportionate share of the expenses of the CMT Fund in which it invests. Vanguard receives no additional revenue from Portfolio assets invested in a CMT Fund.
Temporary Investment Measures
The Portfolio may temporarily depart from its normal investment policies and strategies when the advisor believes that doing so is in the Portfolio's best interest, so long as the strategy or policy employed is consistent with the Portfolio's investment objective. For instance, the Portfolio may invest beyond its normal limits in derivatives or exchange-traded funds that are consistent with the Portfolio's investment objective when those instruments are more favorably priced or provide needed liquidity, as might be the case when the Portfolio receives large cash flows that it cannot prudently invest immediately.
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 an investor 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 investors, 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 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
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investors. 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.
• Certain Vanguard funds charge investors purchase and/or redemption fees on transactions.
You may purchase or sell Portfolio shares through a contract offered by an insurance company. When insurance companies establish omnibus accounts in the Portfolio for their clients, we cannot monitor the individual clients’ trading activity. However, we review trading activity at the omnibus account level, and we look for activity that may indicate potential frequent trading or market-timing. If we detect suspicious trading activity, we will seek the assistance of the insurance company to investigate that trading activity and take appropriate action, including prohibiting additional purchases of Portfolio shares by a client. Insurance companies may apply frequent-trading policies that differ from one another. Please read the insurance company contract and program materials carefully to learn of any rules or fees that may apply.
See the accompanying prospectus for the annuity or insurance program through which Portfolio shares are offered for further details on transaction policies.
The Portfolio, 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: The Portfolio's shares are issued by a registered investment company, 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.
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Turnover Rate
A mutual fund’s turnover rate is a measure of its trading activity. Generally, an index fund sells securities in response to redemption requests or to changes in the composition of its target index. The Portfolio may sell securities regardless of how long they have been held. The historical turnover rates for the Portfolio can be found in the Financial Highlights section of this prospectus. A turnover rate of 100%, for example, would mean that the Portfolio had sold and replaced securities valued at 100% of its net assets within a one-year period. 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 Portfolio and Vanguard
The Portfolio 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.
Investment Advisor
The Vanguard Group, Inc., P.O. Box 2600, Valley Forge, PA 19482, which began operations in 1975, provides investment advisory services to the Portfolio through its Equity Index Group pursuant to the Funds' Service Agreement and
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subject to the supervision and oversight of the trustees and officers of Vanguard Variable Insurance Funds. As of December 31, 2022, Vanguard served as advisor for approximately $6 trillion in assets.
For the fiscal year ended December 31, 2022, the Portfolio’s advisory expenses represented an effective annual rate of 0.01% of the Portfolio’s average net assets.
Under the terms of an SEC exemption, the board of trustees of Vanguard Variable Insurance Funds 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 the Portfolio’s advisory arrangements will be communicated to shareholders in writing. As the Portfolio’s sponsor and overall manager, Vanguard may provide investment advisory services to the Portfolio 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. Vanguard Variable Insurance Funds has 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 Portfolio may rely on the new SEC relief.
For a discussion of why the Board approved the Portfolio's investment advisory arrangement, see the most recent semiannual report to shareholders covering the fiscal period ended June 30.
The managers primarily responsible for the day-to-day management of the Portfolio are:
Donald M. Butler, CFA, Principal of Vanguard. He has been with Vanguard since 1992, has managed investment portfolios since 1997, and has managed the Portfolio since its inception in 1999 (co-managed since 2016). Education: B.S.B.A., Shippensburg University.
Awais Khan, CFA, Portfolio Manager at Vanguard. He has been with Vanguard since 2010; has worked in investment management since 2012; and has co-managed the Portfolio since July 2021. Education: B.S./B.S.B.A., University of North Carolina at Charlotte.
The Portfolio's Statement of Additional Information provides information about each portfolio manager’s compensation, other accounts under management, and ownership of shares of the Portfolio.
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Taxes
The Portfolio normally distributes its net investment income and net realized short-term or long-term capital gains, if any, to its shareholders, which are the insurance company separate accounts that fund your variable annuity or variable life insurance contract. From time to time, the Portfolio may also make distributions that are treated as a return of capital. The tax consequences to you of your investment in the Portfolio depend on the provisions of the annuity or life insurance contract through which you invest; please refer to the prospectus of such contract for more information.
The Portfolio intends to operate in such a manner that a separate account investing only in Portfolio shares will result in the variable annuity and variable life insurance contracts supported by that account receiving favorable tax treatment. This favorable treatment means that you generally will not be taxed on Portfolio distributions or proceeds on dispositions of Portfolio shares received by the separate account funding your contract. In order to qualify for this favorable treatment, the insurance company separate accounts that invest in the Portfolio must satisfy certain requirements. If a Portfolio funding your contract does not meet such requirements, your contract could lose its favorable tax treatment and income and gain allocable to your contract could be taxable to you. Also, if the IRS were to determine that contract holders have an impermissible level of control over the investments funding their contracts, your contract could lose its favorable tax treatment and income and gain allocable to your contract could be taxable currently to you. Please see the Portfolio’s Statement of Additional Information for more information.
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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. The NAV per share is computed by dividing the total assets, minus liabilities, of the Portfolio by the number of Portfolio shares outstanding. On U.S. holidays or other days when the NYSE is closed, the NAV is not calculated, and the Portfolio does not sell or redeem shares. However, on those days the value of the Portfolio’s assets may be affected to the extent that the Portfolio holds securities that change in value on those days (such as foreign securities that trade on foreign markets that are open).
Stocks held by a Vanguard portfolio are valued at their market value when reliable market quotations are readily available from the principal exchange or market on which they are traded. Such securities are generally valued at their official closing price, the last reported sales price, or if there were no sales that day, the mean between the closing bid and asking prices. When a portfolio 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 portfolio 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 portfolio are based on the NAVs of the shares. The values of any ETF shares or closed-end fund shares held by a portfolio are based on the market value of the shares.
A portfolio also will use fair-value pricing if the value of a security it holds has been materially affected by events occurring before the portfolio's pricing time but after the close of the principal exchange or market on which the security is traded. This most commonly occurs with foreign securities, which may trade on foreign exchanges that close many hours before the portfolio's pricing time. Intervening events might be company-specific (e.g., earnings report, merger announcement) or country-specific or regional/global (e.g., natural disaster,
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economic or political news, interest rate change, act of terrorism). Intervening events include price movements in U.S. markets that exceed a specified threshold or that are otherwise deemed to affect the value of foreign securities.
Fair-value pricing may be used for domestic securities—for example, if (1) trading in a security is halted and does not resume before the portfolio's pricing time or a security does not trade in the course of a day and (2) the portfolio holds enough of the security that its price could affect the portfolio's NAV.
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 portfolio to calculate the NAV may differ from quoted or published prices for the same securities.
The Portfolio has authorized certain financial intermediaries and their designees, and may, from time to time, authorize certain fund of funds for which Vanguard serves as the investment advisor (Vanguard Funds of Funds), to accept orders to buy or sell fund shares on its behalf. The Portfolio 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 Portfolio after such acceptance.
The Portfolio’s NAV is used to determine the unit value for the annuity or life insurance program through which you invest. For more information on unit values, please refer to the accompanying prospectus of the insurance company that offers your annuity or life insurance program.
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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.
Yields and total returns presented for the Portfolio are net of the Portfolio's operating expenses, but they do not take into account charges and expenses attributable to the annuity or life insurance program through which you invest. The expenses of the annuity or life insurance program reduce the returns and yields you ultimately receive, so you should bear those expenses in mind when evaluating the performance of the Portfolio and when comparing the yields and returns of the Portfolio with those of other mutual funds.
Mid-Cap Index Portfolio
 
Year Ended December 31,
For a Share Outstanding Throughout Each Period
2022
2021
2020
2019
2018
Net Asset Value, Beginning of Period
$29.48
$25.77
$24.03
$20.23
$23.72
Investment Operations
 
 
 
 
 
Net Investment Income1
.319
.284
.3252
.334
.343
Net Realized and Unrealized Gain (Loss) on Investments
(5.464)
5.642
3.047
5.621
(2.386)
Total from Investment Operations
(5.145)
5.926
3.372
5.955
(2.043)
Distributions
 
 
 
 
 
Dividends from Net Investment Income
(.282)
(.318)
(.344)
(.350)
(.286)
Distributions from Realized Capital Gains
(2.673)
(1.898)
(1.288)
(1.805)
(1.161)
Total Distributions
(2.955)
(2.216)
(1.632)
(2.155)
(1.447)
Net Asset Value, End of Period
$21.38
$29.48
$25.77
$24.03
$20.23
Total Return
-18.82%
24.36%
18.07%
30.87%
-9.33%
Ratios/Supplemental Data
 
 
 
 
 
Net Assets, End of Period (Millions)
$2,231
$2,781
$2,241
$2,155
$1,621
Ratio of Total Expenses to Average Net Assets
0.17%3
0.17%
0.17%
0.17%
0.17%
Ratio of Net Investment Income to Average Net Assets
1.39%
1.03%
1.50%2
1.49%
1.49%
Portfolio Turnover Rate
16%
20%
28%
21%
21%
 
 
1
Calculated based on average shares outstanding.
2
Net investment income per share and the ratio of net investment income to average net assets include $0.036 and
0.17%, respectively, resulting from a special dividend from NortonLifeLock Inc. in February 2020.
3
The ratio of expenses to average net assets for the period net of reduction from custody fee offset arrangements
was 0.17%.
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General Information
This Portfolio of Vanguard Variable Insurance Funds offers its shares to insurance companies to fund both annuity and life insurance contracts. Because of differences in tax treatment or other considerations, the best interests of various contract owners participating in the Portfolio might at some time be in conflict. The Board will monitor for any material conflicts and determine what action, if any, should be taken.
If the Board determines that continued offering of shares would be detrimental to the best interests of the Portfolio’s shareholders, the Portfolio may suspend the offering of shares for a period of time. If the Board determines that a specific purchase acceptance would be detrimental to the best interests of the Portfolio’s shareholders (for example, because of the size of the purchase request or a history of frequent trading by the investor), the Portfolio may reject such a purchase request.
If you wish to redeem money from the Portfolio, please refer to the instructions provided in the accompanying prospectus for the annuity or life insurance program. Shares of the Portfolio may be redeemed on any business day that the NYSE is open for trading. The redemption price of shares will be at the next-determined NAV per share. Redemption proceeds generally will be wired to the administrator within one business day following receipt of the redemption request, but no later than seven business days. Contract owners will receive their redemption checks from the administrator.
Under normal circumstances, the Portfolio typically expects to meet redemptions with positive cash flows. When this is not an option, the Portfolio seeks to maintain its risk exposure by selling a cross section of the Portfolio’s holdings to meet redemptions, while also factoring in transaction costs. Additionally, the Portfolio may work with the insurance companies through which contract owners participate in the Portfolio to implement redemptions in a manner that is least disruptive to the portfolio.
Under certain circumstances, including under stressed market conditions, there are additional tools that the Portfolio 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. The Portfolio may also suspend payment of redemption proceeds for up to seven days. Additionally, under these unusual circumstances, the Portfolio may borrow money (subject to certain regulatory conditions and if available under
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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.
The Portfolio may suspend the redemption right or postpone payment at times when the NYSE is closed or during any emergency circumstances, as determined by the SEC.
The exchange privilege (your ability to redeem shares from one Portfolio to purchase shares of another Portfolio) may be available to you through your contract. Although we make every effort to maintain the exchange privilege, Vanguard reserves the right to revise or terminate this privilege, limit the amount of an exchange, or reject any exchange, at any time, without notice.
The Portfolio may pay redemption proceeds, in whole or in part, by an in-kind distribution of readily marketable securities if Vanguard determines that it would be detrimental to the best interests of the Portfolio's remaining shareholders to pay redemption proceeds in cash.
For certain categories of investors, the Portfolio has authorized one or more brokers to accept on its behalf purchase and redemption orders. The brokers are authorized to designate other intermediaries to accept purchase and redemption orders on the Portfolio’s behalf. The Portfolio will be deemed to have received a purchase or redemption order when an authorized broker, or a broker’s authorized designee, accepts the order in accordance with the Portfolio’s instructions. In most cases, for these categories of investors, a contract owner’s properly transmitted order will be priced at the Portfolio’s next-determined NAV after the order is accepted by the authorized broker or the broker’s designee. The contract owner should review the authorized broker’s policies relating to trading in the Vanguard funds.
Please consult the Portfolio’s Statement of Additional Information or our website for a description of the policies and procedures that govern disclosure of the Portfolio's portfolio holdings.
The Portfolio's Bylaws require, unless the Trust otherwise consents in writing, that the U.S. Federal District Courts be the sole and exclusive forum for the resolution of complaints under the Securities Act of 1933. This provision may limit a shareholder’s ability to bring a claim in a different forum and may result in increased shareholder costs in pursuing such a claim.
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Shareholder Rights
The Portfolio's Agreement and Declaration of Trust, as amended, requires a shareholder bringing a derivative action on behalf of Vanguard Variable Insurance Funds (the Trust) that is subject to a pre-suit demand to collectively hold at least 10% of the outstanding shares of the Trust or at least 10% of the outstanding shares of the series or class to which the demand relates and to undertake to reimburse the Trust for the expense of any counsel or advisors used when considering the merits of the demand in the event that the board of trustees determines not to bring such action. In each case, these requirements do not apply to claims arising under the federal securities laws to the extent that any such federal securities laws, rules, or regulations do not permit such application.
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CFA® is a registered trademark owned by CFA Institute.
Center for Research in Security Prices, LLC (CRSP®) and its third-party suppliers have exclusive proprietary rights in the CRSP® Index Data, which has been licensed for use by Vanguard but is and shall remain valuable intellectual property owned by, and/or licensed to, CRSP®. The Vanguard Funds are not sponsored, endorsed, sold or promoted by CRSP®, The University of Chicago, or The University of Chicago Booth School of Business and neither CRSP®, The University of Chicago, or The University of Chicago Booth School of Business, make any representation regarding the advisability of investing in the Vanguard Funds.
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Glossary of Investment Terms
Capital Gains Distributions. Payments to portfolio shareholders of gains realized on securities that a portfolio has sold at a profit, minus any realized losses.
Common Stock. A security representing ownership rights in a corporation.
Dividend Distributions. Payments to portfolio shareholders of income from interest or dividends generated by a portfolio's investments.
Dow Jones U.S. Total Stock Market Float Adjusted Index. An index that represents the entire U.S. stock market and tracks more than 5,000 stocks, excluding shares of securities not available for public trading.
Expense Ratio. A portfolio's total annual operating expenses expressed as a percentage of the portfolio's average net assets. The expense ratio includes management and administrative expenses, but it does not include the transaction costs of buying and selling portfolio securities.
Inception Date. The date on which the assets of a portfolio are first invested in accordance with the portfolio's investment objective. For portfolios with a subscription period, the inception date is the day after that period ends. Investment performance is generally measured from the inception date.
Indexing. A low-cost investment strategy in which a portfolio attempts to track—rather than outperform—a specified market benchmark, or “index.”
Joint Committed Credit Facility. The Portfolio participates, along with other funds managed by Vanguard, in a committed credit facility provided by a syndicate of lenders pursuant to a credit agreement that may be renewed annually; each Vanguard fund is individually liable for its borrowings, if any, under the credit facility. The amount and terms of the committed credit facility are subject to approval by the Portfolio's board of trustees and renegotiation with the lender syndicate on an annual basis.
Median Market Capitalization. An indicator of the size of companies in which a portfolio invests; the midpoint of market capitalization (market price x shares outstanding) of a portfolio's stocks, weighted by the proportion of the portfolio's assets invested in each stock. Stocks representing half of the portfolio's assets have market capitalizations above the median, and the rest are below it.
Mutual Fund. An investment company that pools the money of many people and invests it in a variety of securities in an effort to achieve a specific objective over time.
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New York Stock Exchange (NYSE). A stock exchange based in New York City that is open for regular trading on business days, Monday through Friday, from 9:30 a.m. to 4 p.m., Eastern time.
Return of Capital. A return of capital occurs when a portfolio's distributions exceed its earnings in a fiscal year. A return of capital is a return of all or part of your original investment or amounts paid in excess of your original investment in a portfolio. In general, a return of capital reduces your cost basis in a portfolio's shares and is not taxable to you until your cost basis has been reduced to zero.
Securities. Stocks, bonds, money market instruments, and other investments.
Total Return. A percentage change, over a specified time period, in a portfolio's net asset value, assuming the reinvestment of all distributions of dividends and capital gains.
Volatility. The fluctuations in value of a mutual fund or other security. The greater a portfolio's volatility, the wider the fluctuations in its returns.
Yield. Income (interest or dividends) earned by an investment, expressed as a percentage of the investment’s price.
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For More Information
If you would like more information about Vanguard Variable Insurance Funds Mid-Cap Index Portfolio, the following documents are available free upon request:
Annual/Semiannual Reports to Shareholders
Additional information about the Portfolio's investments is available in the Portfolio's annual and semiannual reports to shareholders. In the annual report, you will find a discussion of the market conditions and investment strategies that significantly affected the Portfolio's performance during its last fiscal year.
Statement of Additional Information (SAI)
The SAI provides more detailed information about the Portfolio and is incorporated by reference into (and thus legally a part of) this prospectus.
To receive a free copy of the latest annual or semiannual reports or the SAI, or to request additional information about the Portfolio or other Vanguard funds, please visit vanguard.com or contact us as follows:
Telephone: 800-522-5555; Text telephone for people with hearing impairment: 800-749-7273
Information Provided by the SEC
Reports and other information about the Portfolio are available in the EDGAR database on the SEC’s website at sec.gov, or you can receive copies of this information, for a fee, by electronic request at the following email address: [email protected].
Portfolio's Investment Company Act file number: 811-05962
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