Huge Print in Citigroup (C) after an investor buys 180,000 January 2012 puts at the 2.5 line. They paid 23 cents per contract and are possibly closing a position (OI = 390k). It was not tied to stock, according to a source on the exchange floor. C is up 8 cents to $4.55 today and has rallied 43 percent over the past two months. Implied volatility has eased from about 49 to 42 during that time, amid diminishing fears about problems in the financial world. With the focus on the 2012s, today’s put buyer might be looking for the volatility to pick up during the second half of 2010 and into 2011.