The stock market closed mixed Thursday as the Nasdaq again led. The Nasdaq climbed 0.4% thanks to strength in biotech and software stocks. The S&P 500 slipped 0.1%. The Dow Jones industrial average lost 0.2%. Dow component Wal-Mart (WMT) fell 3% after the company gave a weak outlook and announced pay raises for 500,000 workers. Volume fell, according to early figures.