It's actually expected due to the upcoming fork. I agree with the reply that you should hold onto it because the fork this November, as I know, would give bitcoin holders an equivalent amount of coins in another blockchain, thus you would gain more coins that you could probably use to trade or invest. Although, on the one hand, they say that the bitcoin value would decrease for a while. So, if its for investment -- hold it. If it's for money, then sell it before the fork.