U.S. stocks opened higher on Monday after three days of losses, as more merger and acquisition activity and the last days of the third quarter encouraged investor sentiment.

The Dow Jones industrial average <.DJI> was up 40.36 points, or 0.42 percent, at 9,705.55. The Standard & Poor's 500 Index <.SPX> opened up 5.36 points, or 0.51 percent, at 1,049.74. The Nasdaq Composite Index <.IXIC> rose 13.45 points, or 0.64 percent, to 2,104.37.

(Reporting by Angela Moon, Editing by)