Relax kiddo remember newtons law of gravity, whatever goes up must come down 
We are still a few weeks away till halving and we may have seen nothing yet in terms of Bitcoins unstable rise to $700 and close to $800, just hold on to your coins for now but if you are faint-hearted then go ahead and sell, there's a lot of investors out there waiting for someone selling their coins at low price. Patience.