you are probably doing one of the following:
1) buying at or near the open.
2) buying a stock after the market makes its famous 50 point spike in 2 minutes
3) shorting just because something is up and not taking the small loss
4) getting in and out of a stock too many times
5) in a stock for no reason;i like to be in a stock that has a catalyst of sorts. i just don't blindly buy a momo stock just because the market id moving up or down. has to be a reason.
any questions,feel free to pm me.