IT COULD also be high speed computers....that are close to "artificial intelligence" level. Some deal with split second trades...as was noted on 60 minutes I think. It was described as when someone puts in a buy...the "devious computer program" catches it...and by using alternate routes of the internet...can actually get ahead of the buy...and buy in quicky...before the "legitimate buy" hits... so the poor investor buys high...then the computer sells.... That's what we are dealing with...that and much more....Goldman Sachs has a whole floor of such computers doing world wide trading.... its not a "singular" individual behind a computer screen..those days are gone....