BofA (BAC) Feb 13 put is the most actively traded contract in the first hour of trading Thursday. 52.1K traded. Shares are down 37 cents to $16.12 and a block of 46.3K traded at the asking price of 4 cents per contract. It was likely tied to shares because three blocks totaling 3.5 million traded at about the same time. So, this appears to be a protective put strategy where the investor bought shares and puts.