The Morningstar U.S. Mid Cap Growth Index measures the performance of U.S. securities which are assigned to the mid cap index and classified as growth securities by using Morningstar's multifactor model. Morningstar classifies growth securities using the following factors: future longterm growth in earnings per share (EPS), future short-term growth in EPS, 3-year historical growth in EPS, 3-year historical growth in sales per share, current investment-to-assets ratio, and return on assets.