Maybe market just reacted from the recent FUDs which was the hacking of Bithumb and the questions about Bitcoin's legality worldwide and many more. Huge capital was pulled out from the marketcap causing Bitcoin falls down to $6100+. This is not new to me. I think whales are manipulating Bitcoin to scare investors and sell their Bitcoins so they coulld get handful of Bitcoins. Some analysts predicted that Bitcoin could rebound to this price which contrary to what markets movements and it makes investors lose trust to Bitcoin and i think it's a possible reason why Bitcoin dropped $700 of its price. We all don't know what's the reason why it drops hard.