Vanguard S&P Mid-Cap 400 Growth 

The fund employs an indexing investment approach designed to track the performance of the S&P MidCap 400® Growth Index, which represents the growth companies, as determined by the index sponsor, of the S&P MidCap 400 Index. The Advisor 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.