According to some sources, Finance was hacked just to hide the sale bitcoin of the Japanese (mt.gox) ( ~800k BTC ). If there is more information about the hacking exchange. Then, BTC breaking below 4xxx, maybe 2k5, I think the best way: u should to sell all your BTC, altcoin. All exchange will die. That's' the second mt.gox. ***Attention from now until 7/4/2018.
The Chinese exchange is not easy to hack. If so, it is deliberate......
I do not think Bitcoin will reduce $ 4000. Bitcoin will continue to survive at high prices. Although the price of Bitcoin often dropped even once but did not rule out if Bitcoin can continue to survive until whenever. I still believe that Bitcoin still has a bright future.