U.S. Stocks Keeping Gains; Amerigroup Up 3%

Stocks stayed near their intraday highs in afternoon trade Wednesday. The S&P 500 and the NYSE composite rose 0.8% and 1.2%, respectively. The Nasdaq was up 0.5%. Volume was up on both major exchanges. Managed health care provider Amerigroup (AGP) advanced almost 3% in heavy volume. The stock is less than 1% off its 52-week high. Amerigroup is moving from the small-cap S&P 600 to the midcap S&P 400. Precision Castparts (PCP) added 2% in strong