I enjoy holding a stock for a while and seeing how much it's increased in value since I bought it, but really, it's your day to day portfolio gain that matters. So, if you think it's going to go down, sell it. If you think the stock is going to go up, buy it just before it goes up.
Also, stocks don't neccesarily "max out at their release date". They sometimes peak before. Sometimes after. You can base your assumption on how it's being percieved before its release and as it's released -- example, 50 Shades of Grey was heavily anticipated so it seemed wise to load up on it before the release. But it had a low score on Rotten Tomatoes so it seemed that most of the movie-goers who wanted to see it, saw it opening weekend. And, low and behold it dropped off something like 71% in it's second weekend, so it was wise to sell it while it was high from it's open weekend adjustment.
Hope that helps!