Fund Description: Vanguard Extended Duration Treasury ETF is an exchange-traded index fund or Index ETF which is a separate investment portfolio of the Vanguard World Fund, an investment management company. INVESTMENT OBJECTIVE: The Vanguard Extended Duration Treasury ETF seeks to track the performance of Barclays Capital U.S. Treasury STRIPS 20-30 Year Equal Par Bond Index. INDEX DESCRIPTION: The Barclays Capital U.S. Treasury STRIPS 20-30 Year Equal Par Bond Index includes zero-coupon U.S. Treasury securities (Treasury STRIPS) with maturities ranging from 20 to 30 years. A Treasury STRIP represents a single coupon payment, or a single principal payment, from a U.S. Treasury security that has been stripped into separately tradable components. FUND STRATEGY: The Fund employs a passive management or indexing investment approach designed to track the performance of the Index. 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, including duration and other characteristics. All of the Fund’s investments will be selected through the sampling process, and at least 80% of the Fund’s assets will be invested in U.S. Treasury securities held in the Index. The Fund maintains a dollar weighted average maturity consistent with that of the Index, which generally ranges between 20 and 30 years. The Fund is expected to have a duration that is greater than 20 years. FUND MANAGEMENT: The Vanguard Group, Inc. serves as advisor to the Fund.