Bitcoin is still young as compared to all traditional currencies. It will take time to mature and settle in currency world. Bitcoin is a digital currency, it possesses decentralised nature i.e. backed or regulated by no authority. As a result less information and knowledge is available about it. In the last month it has crossed the price tag of $19000, and after that its price is coming down. People having no knowledge of cryptocurrencies started naming this as an end of bitcoin currency and starts comparing t with Dutch tulip mania , the Mississippi bubble and the south sea bubble. This is completely wrong; volatility is the nature of currency.  Being a decentralised currency bitcoin is more volatile than other currencies. Such roll downs are expected after such price raise.