Vanguard Communication Services Index Fund ETF Shares seeks to track the performance of the MSCI US Investable Market Index (IMI)/Communication Services 25/50. The fund employs an indexing investment approach designed to track the performance of the MSCI US Investable Market Index (IMI)/Communication Services 25/50, an index made up of stocks of large, mid-size and small U.S. companies within the communication services sector, as classified under the GICS. The Advisor attempts to replicate the target index by seeking to invest all of its assets in the stocks that make up the index, in order to hold each stock in approximately the same proportion as its weighting in the index. It is non-diversified.