U.S. stocks rose on Monday, with the S&P on track to break a three-day sell-off, after data showed existing home sales rose to their highest level in 2-1/2 years and investors were reassured by a Fed official's comments.

A survey from the National Association of Realtors showed sales of previously owned U.S. homes rose 10.1 percent in October. The Dow Jones U.S. Home Construction index <.DJUSHB> gained nearly 2 percent.

St. Louis Federal Reserve President James Bullard said on Sunday the Fed should extend its mortgage-related assets purchase program to give policy-makers more flexibility.

Stimulative monetary polices are significant positives for the market, and the Bullard comments suggest that the Fed is going to keep policy accommodative for the foreseeable future, said Michael Sheldon, chief market strategist at RDM Financial in Westport Connecticut.

The Dow Jones industrial average <.DJI> gained 158.56 points, or 1.54 percent, to 10,477.47. The Standard & Poor's 500 Index <.SPX> rose 19.43 points, or 1.78 percent, to 1,110.81. The Nasdaq Composite Index <.IXIC> climbed 42.15 points, or 1.96 percent, to 2,188.22.

The U.S. dollar index <.DXY> fell 0.8 percent, sending January crude futures up 2.7 percent.

The Morgan Stanley Healthcare Payor index <.HMO> gained 3.7 percent, while the AMEX Pharmaceutical index <.DRG> was up 1.8 percent.

U.S. President Barack Obama's healthcare reform plan cleared an important Senate hurdle over the weekend, though lawmakers warned of challenges ahead in winning support for passage, even among Obama's fellow Democrats.

(Reporting by Ryan Vlastelica; editing by Jeffrey Benkoe)