people have stop losses in rules about investing i

people have stop losses in rules about investing in a while them to make profit in this game which is very scary some times. I think there is a short position but I think they just slammed on to the momentum in the anytime there's a downward direction just like people buy when there's an upward one. after watching profits disappear many times I make a rule that when the value of the stock in my account goes down after run starts. it's a signal to leave asap.