someone had their shorts closed on bitfinex hence the price hitting $248.5 for a short period of time.
Who knows if someone at bitfinex is actively using insider info to manipulate peoples stops in order to make money off traders or if it just keeps happening so perfectly by chance....
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.
A Bitfinex insider admitted they trade on their own exchange, which is highly unethical with all the insider knowledge they have.