The Nasdaq flattened, the Dow and S&P 500 climbed, and volume rose as earnings news remained the centerpiece of the session's action. The Dow Jones industrial average gained 0.4%. The S&P 500 added 0.5% and the Nasdaq trimmed to a fractional loss. Volume rose about 12% on both the NYSE and the Nasdaq. Energy companies crowded the top gains among S&P 500 stocks: Hess (HES) popped 10%, Valero Energy (VLO) surged 9%, Peabody Energy (BTU) leapt 6%