That flash drop isn't what people really think. Someone just was willing or accidentally sold for that amount. Back in the day, when I would sell coins in 50btc or 25btc increments, they would buy mine even though my price was a bit higher, they didn't want to wait. so, when they bought my coins the price shot up by 20 percent then in the next trade or two, it went back to normal. This was when btc was sub 10 dollars. but I suspect the same thing happened here.. so it really it wasn't a true 309 dollar low, technically it was, but not a true one...
yep propably like 1 was sold for that or even 0,1BTC still was fun ride
to be fair yesterday i did a typo and sold a big numer of coins at 470ish due to typo. luckily it dropped back to 450 later so i bought back before price shoot up.
meh!