U.S. stocks extended gains on Monday on earnings optimism, with the Dow index rising 1 percent, led by gains in Caterpillar Inc .

The Dow Jones industrial average <.DJI> was up 101.27 points, or 1.01 percent, at 10,097.18. The Standard & Poor's 500 Index <.SPX> gained 9.90 points, or 0.91 percent, at 1,097.58. The Nasdaq Composite Index <.IXIC> rose 17.78 points, or 0.82 percent, at 2,174.58.

Caterpillar shares were up 4.8 percent at $57.17 after several positive brokerage notes.

(Reporting by Angela Moon, Editing by Jeffrey Benkoe)