The Dow industrials and the S&P 500 index closed lower on Monday as a decline in oil and other commodity prices hurt energy and materials stocks.
But the Nasdaq ended higher, buoyed by a broker's upgrade on the biotechnology sector.
According to the latest available figures, the Dow Jones industrial average <.DJI> was down 41.34 points, or 0.42 percent, at 9,778.86. The Standard & Poor's 500 Index <.SPX> fell 3.64 points, or 0.34 percent, at 1,064.66.
The Nasdaq Composite Index <.IXIC> rose 5.18 points, or 0.24 percent, to 2,138.04.
(Reporting by Angela Moon, Editing by Kenneth Barry)