US stocks pared opening gains Wednesday as investors expected the Federal Reserve would announce new support for the sluggish economy following a two-day monetary policy meeting.
The Dow Jones Industrial Average was up a scant 8.15 points (0.06 percent) at 13,256.59 by 1540 GMT, after a five-day winning streak.
The S&P 500-stock index advanced 1.94 (0.14 percent) to 1,429.78, while the tech-rich Nasdaq Composite edged up 0.29 (0.01 percent) to 3,022.59.
"Wall Street is speculating the Fed will replace the expiring Operation Twist program with a fresh round of Treasury purchases," said Karee Venema of Schaeffer's Investment Research.
The central bank's Federal Open Market Committee is due to announce its monetary policy update at 12:30 pm (1730 GMT).
On the Dow, Bank of America was up 0.4 percent and JPMorgan Chase surged 1.1 percent.
DuPont led the blue chips higher, jumping 1.8 percent, after announcing a $1 billion share buyback program and updated its 2012 earnings outlook to the high end of its prior guidance.
On the Nasdaq, heavyweight Apple fell 0.7 percent. The Wall Street Journal reported the company is working with component suppliers in Asia to test TV set prototypes, suggesting a possible move into the TV market.
Costco Wholesale rose 0.4 percent. The warehouse club retailer posted first-quarter fiscal earnings that topped Street expectations.
Rare-earth miner Molycorp dropped 0.7 percent after the unexpected departure of chief executive Mark Smith.
On Tuesday, technology shares underpinned Wall Street gains. The Dow added 0.60 percent, the S&P 500 rose 0.65 percent and the Nasdaq 1.18 percent.
Bond prices were mixed. The 10-year US Treasury yield rose to 1.66 percent from 1.65 percent late Tuesday, while the 30-year was unchanged at 2.84 percent.
Bond prices and yields move inversely.