Someone as been putting up huge bids on OKCoin - 3500 BTC each, 10 kBTC or more total - and playing around with them.
... and the Phantom Bearwhale is gone ...
Perhaps some wealthy OKCoin client living in the US got excited about the BitcoinBowl commercials... but then pulled back when he realized no one was following?
Oops, he still seems to be around -- but with smaller bids, 1000 BTC or so.
About 7000 BTC were traded in the last 15 minutes, so he cannot have bought too much.
EDIT: back with a 4000 BTC bid...
EDIT2: then he puts a 3000 BTC sell order, some 20 CNY above the previous buy orders. At least he knows the basic "buy low, sell high" rule.