One thing is truly incredible to me. This post suggests highly manipulated stock market on intraday basis, yet lots of people swear by stock trading against E-minies. Personally, I have experience with stocks and SPY and do not see any difference in level of difficulty. However it seems to me that it is probably more profitable to go beyond the noise level. Otherwords from "1 min. to 2hr" to "1 hr to overnight" timeframe.