player...no worries, as OM says, it will bounce back inevitably. If you are a day trader, then you have to qualify your stocks you are holding and attempt to be predictive of their movement. I have been too busy to day trade effectively so I have lost money on quite a few bounces...I have to make the call...is the stock bouncing or diving or rising for a short term...long term...or what.
Reset still affects a few stocks. It can hurt if you want to day trade and you miss a flip.
But here is the best advice I can give you...forget your losses by making them back with another good purchase. You are going to make fake money...you are going to lose fake money. Sometimes it is fair and sometimes the mechanics of the game screw the hell out of you. We have to work with the game given us and movement like that is not going to change. I would either ride it out if you think the move will reverse or sell and move to a better target.
One of my tricks a short term memory. But that is in regards to the sting of the loss...if I can learn from that loss, I retain that to avoid it in the future. 