The major averages appeared headed for a fourth straight gain Thursday before a late rally fizzled in light Christmas Eve trading. The Nasdaq edged up 0.1%, while the S&P 500 dipped 0.2% and the Dow Jones industrial average slid 0.3%. Volume fell on both the NYSE and the Nasdaq in the shortened preholiday session. In the stock market today, recent IPO stock CSRA (CSRA) jumped 4% to lead the S&P 500.