Pump and dump or was it a well calculated move?

Yesterday, we were trading in a tight bull flag at around 242. I made a call and went long at this area expecting a breakout higher. I did not capitalize it, got shaken out before the rise. However, I've noticed something very interesting. There was a huge margin call on the short side valued at 11825 contracts. Take a look at the numbers below. How big is this size? the second largest account holder on OKcoin.

Somebody got absolutely recked by this move up. Whether this move is manipulated or not. Take a look at the top trader sentiment chart below:

Looks familiar? The 11825 contracts that got called was the number 2 guy. Shortly after he got called, market sold off. He single handed dropped weekly futures' open interest. I call that buying climax.