Stocks were mixed, but gained a small amount of ground in afternoon trading Friday. A better-than-expected retail sales report lifted Wall Street spirits in the stock market today. The Nasdaq gained 0.1%; the Dow Jones industrial average dropped 0.1%, and the S&P 500 was flat. Volume was running lighter than Thursday’ pace. The government reported retail sales rose 0.3% vs. a 0.2% consensus estimate among economists.