Fund is an actively-managed exchange-traded fund (ETF) that seeks to achieve its investment objective by investing in one or more other ETFs that seek to obtain exposure to the performance of US short-term treasury bills, typically less than 90 days in duration, or directly in the securities held by such ETFs (collectively, the Underlying Investments) and selling and purchasing S&P 500 Index put options (SPX put options) to generate income to the Fund beyond what is received from the Underlying Investments. The Fund invests under normal circumstances at least 80 percent of its assets in a diversified portfolio of fixed-income securities of varying maturities, which may be represented by ETFs that invest 80 percent or more of their assets in US short term treasury bills, and forwards, options, futures contracts or swap agreements related to such bills. For purposes of the 80 percent policy, the value of such options, futures contracts and swap agreements shall be determined on a daily mark-to-market basis.