I have been trading this fading strategy for just over one year. Profits are very volatile since I don't use stop losses. The strategy basically sells strength, buys weakness and waits for the opposite to happen or a time-frame to finish. Only trade at end of day with +- 50 reversals in the time period. Only 1 ES contract traded at a time. Is patience rewarded that much when trading the S&P 500?
You should ask yourself if you want to trade a system that didnt make any money since its equity high in september and generated huge drawdowns in between.
You need more then that. If you were selling against a resistance or support number then it would be more viable. Also I've noticed on days where the dow is up or down more then 150 there is no reversal, we usually close on the lows/highs.
i think its sustainable - providing you risk only a small % on each trade to avoid the strings of drawdowns carrying you out. perhaps testing in a variety of market conditions may also help jmo