Wall Street ended little changed on Tuesday as healthcare gains countered declines in energy shares, a day before highly anticipated outcomes of monetary policy meetings in the United States and Japan.
Though the Federal Reserve is not expected to raise rates on Wednesday, investors will comb the U.S. central bank's statement for any clues about whether it will hike in coming months.
The Bank of Japan is expected to further ease its ultra-loose policies, according to a Reuters poll of economists.
"Not many think the Fed is going to hike tomorrow, but whether they change the language to get a little more hawkish, there’s been conversation around that," said Walter Todd, chief investment officer at Greenwood Capital in Greenwood, South Carolina.
"The Bank of Japan is a whole other issue unto itself ... Given the level of uncertainty around those two meetings, I just think people are kind of biding their time."
The Dow Jones industrial average .DJI rose 9.79 points, or 0.05 percent, to 18,129.96, the S&P 500 .SPX gained 0.64 points, or 0.03 percent, to 2,139.76 and the Nasdaq Composite .IXIC added 6.33 points, or 0.12 percent, to 5,241.35.
Traders are projecting an 18-percent chance that the Fed will raise rates on Wednesday, but the probability rises to 60 percent for a hike at its December meeting, according to the CME FedWatch website.
A report on Tuesday showed U.S. housing starts fell more than expected in August.
"It would seem at this point that, with all the recent economic data coming in just a little bit soft, that any move by the (Fed) would be a pretty nasty surprise," said Eric Kuby, chief investment officer at North Star Investment Management in Chicago.
The healthcare sector .SPXHC was the best performing major S&P sector, rising 0.4 percent.
Allergan (AGN.N) said it would pay up to $1.7 billion to buy Tobira Therapeutics (TBRA.O), which is developing therapies for NASH, an incurable fatty liver disease. Tobira shares soared more than 700 percent, while Allergan shares fell 2.7 percent.
Shares of Gilead Sciences (GILD.O), which is also developing drugs for NASH, rose 3.5 percent and gave the biggest boost to the S&P and the Nasdaq.
Wells Fargo (WFC.N) shares rose 1.2 percent after the bank's chief executive weathered criticism as he testified before a U.S. Senate panel.
Energy shares .SPNY were the worst performing group, falling 0.8 percent. Exxon (XOM.N) fell 1.5 percent. A Wall Street Journal report said the U.S. Securities and Exchange Commission is investigating how the oil major valued its assets in the wake of the plunge in oil prices.
FedEx (FDX.N) shares rose more than 1 percent in extended trading after the package delivery company reported results.
About 5.8 billion shares changed hands on U.S. exchanges, below the 6.7 billion daily average for the past 20 trading days, according to Thomson Reuters data.
Declining issues outnumbered advancing ones on the NYSE by a 1.28-to-1 ratio; on Nasdaq, a 1.10-to-1 ratio favored decliners.
The S&P 500 posted 3 new 52-week highs and 4 new lows; the Nasdaq Composite recorded 77 new highs and 33 new lows.
(Additional reporting by Yashaswini Swamynathan in Bengaluru; Editing by Chizu Nomiyama and Nick Zieminski)