NEW YORK (TheStreet) -- JPMorgan Chase may not end up buying back too much stock this year, if the current strength in the stock persists. In his annual letter to shareholders, CEO Jamie Dimon said the bank's appetite for buying back stock at current levels of around $45 is "not as great", as shares now trade well above tangible book value per share. "If you like our businesses, buying back stock at tangible book value is a very good deal.