Vanguard Total Bond Market ETF (the Fund) seeks to track the performance of a market-weighted bond index. The Fund employs a passive management or indexing investment approach designed to track the performance of the Barclays Capital U.S. Aggregate Bond Index (the Index). The Index measures a spectrum of public, investment-grade, taxable, fixed-income securities in the United States, including government, corporate and international dollar-denominated bonds, as well as mortgage-backed and asset-backed securities, all with maturities of more than one year. The Fund invests by sampling the Index, meaning that it holds a range of securities that, in the aggregate, approximate 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 at least 80% of its assets will be invested in bonds held in the Index. The Fund's investment advisor is The Vanguard Group, Inc.