Stocks remained in the black in early-afternoon trade Wednesday, but were still well off early-morning highs. The S&P 500 was up 1.3% while the Dow Jones industrials rallied 1.4%. The Nasdaq was up 1.2%. Volume grew on the NYSE and was mildly down on the Nasdaq exchange compared with the same time Tuesday. In the stock market today, some of the heavily battered industry groups paced the advance.