Wall Street has shifted from small gains to losses before the opening bell after some high-profile companies revealed some weaknesses in the just finished quarter. Futures for the Dow were down 0.2% before the bell Thursday, while the S&P 500 dipped 0.1%. Delta tumbled more than 8% after it reported lagging profits. The Atlanta airline's results dragged other airlines lower, with United and American falling 4.5% and Southwest and JetBlue each losing 2.6%. PepsiCo fell more than 2% after reporting weakening demand. Later Thursday, the U.S. government will release data on consumer prices, which the Federal Reserve will consider at its next policy meeting later this month.