REK provides inverse exposure to the S&P Real Estate Select Sector Index a market cap-weighted index of US real estate companies, as classified by S&P Dow Jones. Although REK is not a leveraged fund, its daily rebalanced inverse exposure exposes the fund to issues of compounding and path dependency. As a result, the long-term returns of the fund are impossible to predict when compared with its beta-1 cousin, IYR. For this fund, investors must monitor and rebalance their exposure whenever possible. The index undergoes annual reconstitution and quarterly review. Prior to March 17, 2023, the fund tracked the Dow Jones US Real Estate Index.