Your question can not be answered because it depends greatly on personal circumstances.   The really simple answer is that there's no good time to sell if you don't really need to, so long as Bitcoin is a viable product it's very likely to keep gaining in the long run.   Decide when to sell if you don't believe that BTC is a viable alternative to fiat and there's your choice, otherwise it's a brand new product, a market that never existed before and you're fortunate to see it all start.