...Is that what's happening right now? The classic age-old investing advice? Everyone's buying like crazy on the "rumour" in preparation for a big dump on the news? It would have to be a pretty big dump to counter-act the sudden mining supply halving, but whatever, sentiment can be pretty strong in either direction.
If you are in profit, then it makes sense to realise some of it. That way you won't feel bad if it tanks. If you bought in at $200, then sell half, and at least you will have got your initial capital back, and the rest is just a fun gamble!
I think it was the Rockerfellers who said "No one ever got poor by taking profits".