Many government has said it will tighten virtual currency management, causing Bitcoin prices to fall below 9,000$.
Bitcoin prices traded on Coinmarketcap at 8:40 am on Feb. 2 were around 8,779.76$, losing more than 14 percent of yesterday's value.
Compared to the peak set in December 2017, Bitcoin lost more than 60% of its value.

The Government seems jealous to bitcoin, being itself decentralized yet so expensive makes the Government to envy it and doing things that they think could destroy bitcoin slowly and so on(though there are some countries exception here). China is one of the countries showing envy to bitcoin, they banned ICO's and their local exchangers and that caused bitcoin's price to crashed.
We don't know when will be the bitcoin's price is going to be stable again, for now, we should just hold our bitcoin, have patience on waiting until it skyrocket again to not waste profits.