They dumped 1,150 bitcoins 5 days ago when the price was $590, 1,350 3 days ago when the price was $550, and now they have dumped 1,237 more TODAY when the price was $510, that`s why we went down 500usd and we are going to $450...
How do you know this? Is the address they're sent to a known address of a trading site?
They admit the needed of selling bitcoins till reach 3 millon USD. So there`s a lot of dumping incoming.