Some people will dump a stock that's risen alot to take the profit and get out regardless of further profit that might be made while others will stick around for the extra profit.
Some follow the market minute by minute and dump (or buy) at the slightest change. It also depends on the stock price. $20 stock has small commission that can be easily made up while a $300 stock will need $6 change if you flip it.
Movies often climb on anticipation and fan excitement and then can crash when reality sets in with the projections that come in the week before it opens. The 1st projections can come in Sunday night or Monday when opening weekend coverage is over and time to move on to the next weekends movies. Some people wait till Thurs night or Fri morning to dump when you get 1st report of actual attendance.
You have to decide what amount of risk you want to take and what you think the movie will make for the weekend vs it's current price