So, all you folks who try and sell at the start of a big crash to buy in nearer the bottom. Do you keep your coins in an exchange ready for such an event, or do you move them across when you think the time is near?

I saw there was a guy in this thread who went from 50 to 70 doing so - that doesn't sound like day trade play money. I'd be concerned about leaving a big stash of BTC in an exchange given how Wild West some of the BTC world is. I guess the chances are small if it's just temporary, but would any of you be concerned that BitStamp or Gox could get hacked, or go out of business, for example?