For me I don't see any special factor affecting the decline of Bitcoin rather the huge amount of Bitcoin sold is the cause of it declined.  When Mr A sell and Mr B sees that the market is declining, he also sell and Mr C sell just like the selling oder become higher than the buy oder then the price starts falling untill more investors begins to buy back and the market start to turn green again for me there is no magic about that. When the buy oder is higher than the sell oder it grows up. But when the sell oder becomes high , there will be declined in market. It's just vise versa.