As of now, the panic has kinda set in someplaces where we see BTC's plummeting down by more than $1k is being called as bloodbath.
The following is a speculation that is seen doing rounds in some of the websites.
The most speculated reason I understand is because of rumours that bitcoin prices are controlled by bitcoin whales, according to Bloomberg, is about 1000 people, that hold about 40% of the bitcoins.
One such whale they say is now defunct Mt. Gox exchange's attorney called Nobuaki Kobayashi, has said, he is raising money to pay off Mt. Gox creditors.
It is also said that he holds about $2 billion worth BTCs and out of this, already $400 million dollars of BTC & BCH combined together has been sold, which is setting off panic in the market already.
All said and done, HODL. I don't think there is any going back and there is always resistance that is going to be offered through multiple means. If there is something that climbs up, it will come down and then again, there's climbing up. Nothing can stay afloat all the time and nothing can remain buried all the time either.
Invest sensibly when its in RED and push things off when it's in GREEN.
Cheers !!!!