Before entering a trade, know how much you wish to take out of the trade, or how much you are willing to lose. If it goes beyond that point on the upside, follow it with a trailing stop. Do not sit back and hope that it is going to keep going up without a trailing stop in place, I have seen more people lose their "acceptable profit, by holding out for "greed without a trailing stop"
Don't buy/sell the stock because I did! Unless you want to lose money too!!