radian group, mgic and mbia each fell. radian and mgic hit new 52-week lows. morgan stanley was the best financial stock, rising more than 11%. volume more than tripled. this stock was at a 52 week low on monday. the bank lost only about half as much as analysts had feared in the second quarter. revenues were strong, thanks to underwriting several hot initial public stock offerings this spring. a big deal in pharmacy benefits management. express scripts will buy medco health for just over $29 billion in cash and stock. medco shareholders will get just over $71 per share. medco was one of the most actively traded issues today, up 14%. it closed shy of the buyout price, perhaps reflecting some concern about getting the necessary regulatory approval. still, the deal got an endorsement with the buyer's stock price moving higher. express scripts added 5%. five years ago, express scripts tried unsuccessfully to buy caremark. instead, drug store cvs bought it, creating cvs caremark. its shares were up 2%, while competitor walgreen dropped 5%, dropping below $40 for t