I know its all still because mt gox scandal hacking. A lot of btc hacked and mt gox also still have 200k bitcoin and 200k bcash. They need to sell it now because they can pay all customer with this price. All mtgox customer paid by dollar and 1 btc = $400. We will see another dump in the next couple of week untill all sold or mayber mt gox trustee will wait btc price up again then sell for bigger bucks.
he wont sell all because he just has to sell enough to payback investors than he will give rest of btc to Mt.Gox. The problem is why Trustee doesnt make an Auction ? Its best way to sell btc . Who buy btc wont sell maybe but HODL so btc will not dumped anymore. They have another meeting in September 2018 i hope thiş time they wont sell..
perhaps this is a pre-planned attack on the market, so that people begin to panic. Already at a very inappropriate time, the sale of so many bitcoins was made.