Citi (C) calls are seeing heavy trading as shares gain 22 cents to $3.78, session highs and their best levels of 2010. 165.6K April 4 calls traded (37% Mid / 52% Ask), 138.5K Mar 4 calls (78% Ask), and 54.8K Jun 4 calls traded (27% Mid / 55% Ask). An impressive 581K Citi calls traded so far and trading is still brisk. Implied volatility is down about 2.5 percent to 49. The bullish flow comes amid mixed action in the financials Monday, but seems to reflect some optimism that the worst might be over for Citi shareholders.