Stocks in the News: Express Scripts, General Motors, Boeing, American Express

It's shaping up to be an interesting day.

Shares of Express Scripts Inc. (ESRX) gained in pre-market trading after it agreed to buy WellPoint Inc.'s (WLP) pharmaceutical benefit management businesses for about $4.68 billion.

As Bloomberg News notes, "Express Scripts lost a hostile takeover bid two years ago for rival benefits manager Caremark Rx Inc., which was acquired by drug store chain CVS Corp. for $27.5 billion. The WellPoint acquisition will give Express Scripts more clout in negotiating lower prices on prescription medicine."