Stocks opened slightly higher in uneven trade Friday, as investors pored over incoming company news and mixed industrial data. The Nasdaq, the S&P 500 and the Dow Jones industrial average added 0.2% apiece. Trading swelled 214% higher on the NYSE as Wal-Mart (WMT), Coca-Cola (KO) and Exxon Mobil (XOM) all lost ground in massive trade. Action was 2% higher on the Nasdaq, compared with Thursday morning's levels. Industrial data sent mixed signals