Thanks for the information; It seem that what you are looking at in real time is too fast to even scalp. That is, by the time your program trading has kicked in and the comp has failed to move, the chance , say to short the qqq is gone. The next move could by a violent spike up, this time with no selling; so it looks to me like guessing. But, I have no experience with doing it, so I must be missing something, Thanks, Rick