Stocks are wavering between small gains and losses as several big U.S. companies report their fourth-quarter financial results.
The Dow Jones industrial average was up four points at 13,654 shortly before noon Tuesday.
The Standard & Poor's 500 index fell two to 1,484. The Nasdaq composite average dropped 10 points to 3,124.
Chemical and bioscience company DuPont reported a sharp drop in income, but the results still beat analysts' forecasts. DuPont's stock rose 1.6 percent.
Johnson & Johnson fell 1 percent after issuing a forecast for 2013 income that fell short of analysts' estimates.
IBM and Google report their results after the closing bell.
The market was closed Monday for the Martin Luther King Jr. holiday.