Considering 30-days investment horizon, Chevron Corporation is expected to under-perform the Exxon. In addition to that, Chevron is 1.03 times more volatile than Exxon Mobil Corporation. It trades about -0.13 of its total potential returns per unit of risk. Exxon Mobil Corporation is currently generating about -0.03 per unit of volatility. If you would invest  9,280  in Exxon Mobil Corporation on May 20, 2013 and sell it today you would lose (87.00) from holding Exxon Mobil Corporation or give up 0.94% of portfolio value over 30 days.