Ah, that explains the giant 5k buy on Bitfinex that sent the price up everywhere else. This happens every so often when you get someone doing massive gambles on leverage. It's surprising that people risk having such big sums of money on that exchange now that there are reports of negative account balances and orders not getting filled.
Lots of traders are looking for a new home.
https://www.reddit.com/r/BitcoinMarkets/ is a good place to keep track of their gripes. There are certainly no shortage of them.
Once someone comes up with an exchange with all the bells and whistles that actually works and has the necessary liquidity they'll clean up.