it depends, if you were just investing for instant gains, yes you should sell it just before it crashes. But if you believe in the currency (roadmap, people behind it, uses to your life in the future) then you should just stick to it. But in my opinion, it wil eventually crash and stay there for a while due to the debate in its uses and people behind it. There will always be a reason for it to crash. So watch it carefully and goodluck.