By David Russell, reporter at OptionMonsterNEW YORK -- CNO Financial ( CNO)has been pulling back, and now the bulls are stepping in. OptionMonster's tracking programs detected the purchase of about 2,400 December 8 calls for 50 cents and 55 cents. Volume was more than 39 times open interest in the strike, so the activity resulted from new positions being initiated. Those calls lock in the price investors must pay to own shares in the provider of insurance and annuities. They can deliver significant leverage if the stock rallies, but also stand to expire worthless if it fails to move or appreciates too slowly. CNO rose 3.36% to $7.07 Thursday. It peaked around $8.20 in late March, but has been following other financial stocks lower since then. The last earnings report on April 30 beat estimates, and the company trades for less than half book value. Overall options volume was 12 times greater than average in the session, with calls outnumbering puts by more than 280 to 1.