Multipools cause 80% value drop
In just one day, Dogecoin drops from $0.0003 to $0.0002 due to an exploit that makes Dogecoin easy to mine with very little computing power. Multipools take advantage of this by mining large amounts of Dogecoin and selling it immediately. Dogecoin co-founder Billy Markus says:
Basically multipools (and probably people too) sold a lot and ate up all the bids.