1% envelope (half a percent on either side)
fair value adjusted for beta
example:
spm down .47%
gm close 61.00
fairvalue = (-.0047 * 1.13(beta) +1) * 61 = 60.68
buy at 60.37
sell at 60.98 (so if it opens up, or unch on uptick, you're short)
stock opened and was filled long at 60.05, sold at 60.15
Are you using a larger envelope?
I'm getting typically 3 fills a day on just 10 or 11 stocks. Actually had only 10 today, cause I had IP but cancelled it on news of major downgrade. It would have been a loser.