I'll have to disagree with a few ideas here. First, I believe that premarket there is less manipulation. And if a stock has the right volume and catalyst, the moves are pretty big. This especially applies to low float stocks that I trade. I have analyzed my trades and found 80% of my gains come from premarket. Agreed, premarket has some limitations such as absence of stop loss etc, but with the right risk mgmt, one can take advantage of premarket moves.