The investment seeks to provide investment returns that correspond, before fees and expenses, generally to the performance of the Fidelity U.S. Low Volatility Factor Index?. The fund normally invests at least 80% of assets in securities included in the Fidelity U.S. Low Volatility Factor Index?, which is designed to reflect the performance of stocks of large and mid-capitalization U.S. companies with lower volatility than the broader market. It may lend securities to earn income for the fund.