I think that it was really strange that in January when BTC went down all big cryptocurrency exchanges closed registration for new members and they opened it only when the price was low. Then at spring when the downtrend was broken(7000$) there were many news that cryptocurrency now will go up! But whales just made big shorts at 10 000 $and all the news said that cryptocurrency won't go up for along time and market went down to current position.
There's are no basis and there no evidence accussing of exchnage close for new member to manipulate the bitcoin price in the market, either the platform closing for awhlie for the new members are need to upgrade the system to give better service from all users.