The Nasdaq erased a 1% gain Thursday and was mostly unchanged with less than two hours to go in the session. The S&P 500 was also unchanged, while the Dow Jones industrial average gained 0.3%. Volume on the NYSE was tracking about 8% lower than Wednesday. Nasdaq volume fell 5%. In the stock market today, Priceline.com (PCLN) was trying to hold its 200-day moving average. Shares fell 0.6%.