I want to sell a sequence of one-month, at-the-money, S&P 500 Index puts and invest cash in one- and three-month Treasury Bill rates. The number of puts to be sold varies from month to month. The number of puts sold increases with Treasury Bill rates and the price of the put, and decreases with the strike price of the put. Do you think it is a good strategy to earn RISK FREE $$$$$ ??