Fund Description: Vanguard Mid-Cap ETF, formerly Vanguard Mid-Cap VIPERs, is an exchange-traded index fund or Index ETF which is a separate investment portfolio of the Vanguard Index Funds an open-end investment management company. INVESTMENT OBJECTIVE: The Vanguard Mid-Cap ETF seeks to track the performance of the CRSP US Mid Cap Index, formerly the MSCI US Mid Cap 450 Index. INDEX DESCRIPTION: The CRSP US Mid Cap Index measures the investment return of mid-capitalization stocks. The Index is a broadly diversified Index of stocks of medium-size U.S. companies. FUND STRATEGY: The Fund employs a passive management or indexing investment approach designed to track the performance of the Index. As its primary indexing strategy, the Fund 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. The Fund may use a sampling strategy if regulatory constraints or other considerations prevent it from replicating the Index. FUND MANAGEMENT: The Vanguard Group serves as investment advisor to the Funds.