Stocks rose slightly Thursday, with the Nasdaq composite closing at a record high for the first time since the dot-com bubble of 2000. On Thursday: The Dow Jones industrial average was up 20.42 points, or 0.1 percent, to 18,058.69. The S&P 500 index rose 4.97 points, or 0.2 percent, to 2,112.93. The Nasdaq composite gained 20.89 points, or 0.4 percent, to 5,056.06. For the week: The Dow is up 232.39 points, or 1.3 percent.