Assuming 30 trading days horizon, S&P 500 is expected to under-perform the Procter. But the index apears to be less risky and, when comparing its historical volatility, S&P 500 is 1.65 times less risky than Procter. The index trades about -0.12 of its potential returns per unit of risk. The Procter Gamble Co is currently generating about -0.04 of returns per unit of risk over similar time horizon. If you would invest  7,882  in Procter Gamble Co on May 21, 2013 and sell it today you would lose (121.00) from holding Procter Gamble Co or give up 1.54% of portfolio value over 30 days.