Everyone has there own trading style. And, ofcourse it depends on when you bought it, but even if you invest long term, it's smart to exit the BTC if the trend goes down. You don't know for how long it will dump.

Look at the charts below. I got out of the bitcoin when it dumpt on 12 june, at $2560. Today we are at $2264. This is a dump of $300 per coin. I personly don't like to loss money.

http://i.imgur.com/ZGjMuiF.jpg