The investment seeks to track the performance of a benchmark index that measures the investment return of mid-capitalization growth stocks in the United States. 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 of the S&P MidCap 400 Index. The index measures the performance of mid-capitalization growth stocks. It 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.