The investment seeks investment results that, before fees and expenses, generally correspond to the performance of the CBOE S&P 500 BuyWrite Index. The fund invests at least 80% of its total assets in the securities of the underlying index. The underlying index measures the performance of a hypothetical portfolio that employs a covered call strategy. A covered call strategy is generally considered to be an investment strategy in which an investor buys a security, and sells (or writes) a call option on that security in an attempt to generate more income.