Volume of that coinbase dump was 1690 btc, pretty intense.
actually 1690btc to drop the price 200$ which is almost 20% is ridicolous low.
Lets assume other sites trade after this then they get screwed.
Marketcap is 20billion so 2million is nothing.
I wont make my decision after a 2 million $ drop.
The point is the orderbooks getting thinner as the ETF decsison is knocking and noone wants to have orders in the book in the wrong direction.
I think this wont affect BTC overall price, a dump in a single exchange can easily be recovered once buyer from other exchanges realized this. They will move their funds towards that exchange and buy them enjoying the profit. And that is what actually happen when it quickly recover back to the real price.
Or probably a whale just messed up his buy order (as stated of one of the earlier reply) clicking sell order instead LOL,