U.S. stocks fell on Wednesday, as a weak outlook from Texas Instruments weighed on the Nasdaq and pushed an index of chip makers below a key technical level in a worrisome sign for the market's six-month uptrend.

The PHLX semiconductor index <.SOX> fell 3 percent to close below its 50-day moving average, which represents medium-term momentum, for the first time since September.

The Dow Jones industrial average <.DJI> dipped 1.29 points, or 0.01 percent, to end unofficially at 12,213.09. The Standard & Poor's 500 Index <.SPX> shed 1.80 points, or 0.14 percent, to finish unofficially at 1,320.02. The Nasdaq Composite Index <.IXIC> dropped 14.05 points, or 0.51 percent, to close unofficially at 2,751.72.

Texas Instruments led the losers, after its earnings target disappointed Wall Street. Its stock fell 3.1 percent to $34.74.

(Reporting by Angela Moon, Editing by Jan Paschal)