The investment seeks to replicate as closely as possible, before fees and expenses, the price and yield performance of the S-Network Municipal Bond Closed-End Fund IndexSM (the CEFMX Index). The fund normally invests at least 80% of its total assets in investments the income from which is exempt from U.S. federal income tax (other than federal alternative minimum tax). It normally invests at least 80% of its total assets in securities of issuers that comprise the fund's benchmark index. The CEFMX Index is comprised of shares of U.S.-listed closed-end funds.