Quote from mcurto:
Surprisingly 107 volatility was only bid by about .10% in Feb so they really didn't get hit too hard today. I think they sold however many futures up around 29 to 27.5 to hedge out that gamma (but probably didn't plan on a move this huge today). They sold about 50,000 March 106 puts vs. futures today around a 3.90% vol, which should be a new position (will have to take a look at open interest tomorrow).
It looks like OI on the Mar 106p did not move very much on a net basis. But I assume that convexity hedging was also active as 4.85 was taken out.