The investment seeks to provide investment returns that correspond, before fees and expenses, generally to the performance of the Fidelity U.S. Momentum Factor Index?. The fund normally invests at least 80% of assets in securities included in the Fidelity U.S. Momentum Factor Index?, which is designed to reflect the performance of stocks of large and mid-capitalization U.S. companies that exhibit positive momentum signals. It may lend securities to earn income for the fund.