Stocks were little changed in early trading on Tuesday ahead of a statement from the Federal Reserve on monetary policy and the state of the economy.
The Fed is seen holding interest rates near zero, and analysts widely expect the bank's statement to say again that high unemployment and low inflation warrant holding borrowing costs exceptionally low for an extended period.
That stance has helped stocks rally as the flow of cheap money encourages investors to look for returns in riskier assets.
The U.S. dollar dipped on the expectation of low interest rates, lifting crude and gold prices and giving a boost to materials shares.
The S&P materials sector <.GSPM> rose 1 percent with miner Cliffs Natural Resources Inc
We're seeing hesitation before the Fed announcement this afternoon, said Dan Cook, senior market analyst at IG Markets in Chicago.
He said he doesn't expect the Fed to extend its buying of mortgage-backed securities, which has been winding down and is expected to end this month, but the market will be hesitant if there are any unexpected news on the subject.
The Dow Jones industrial average <.DJI> gained 0.38 point, flat in percentage terms, to 10,642.53. The Standard & Poor's 500 Index <.SPX> rose 1.91 points, or 0.17 percent, to 1,152.42. The Nasdaq Composite Index <.IXIC> added 1.90 points, or 0.08 percent, to 2,364.11.
Healthcare sector stocks fell after Goldman Sachs said in a research note it sees a more than 50 percent chance healthcare overhaul legislation will pass Congress and adjusted its ratings on several companies.
Goldman removed Teva Pharmaceutical Industries
The Morgan Stanley healthcare payor index <.HMO> fell 0.3 percent.
Discussions of healthcare reform have made investors cautious as they scramble to gauge the implications of legislation on profits for the sector's companies.
(Editing by Padraic Cassidy)