i don't think that Ok coin, Huobi itself is cheating in the bitcoin price. but more likely users in their site is cheating the bitcoin price using allied. Huobi cannot legitimately control the price of bitcoin otherwise would probably seized by the chinese government.of course, the exchangers are manipulating the market. it's impossible to have such volumes and it was proved that the volumes are fake. some of them admitted.
Without fake volumes, the whole market will be like a desert.