This binary model switches between SPY (SPDR® S&P 500® ETF) and SH (ProShares Short S&P500 ETF) depending on market direction. Using a web-based trading simulation platform, our ranking system, and specific buy and sell rules, this model would have produced an average annual return of about 27.7% from January 2000 to middle of August 2013, versus 2.8% for a buy-and-hold investment of SPY over the same period.