Speeches from a number of policymakers on Monday suggested that the Fed may be closer than previously thought to trimming its $85 billion a month in bond purchases. The stimulus program has helped drive the US stock market's rally this year.
A recent string of strong economic data, however, has removed some of the market's anxiety about the eventual ending of the Fed's quantitative easing program.
A Reuters poll showed on Monday that economists expect the Fed to begin trimming its quantitative easing program in March, but some are warming up to the idea that it will do so as early as this month or at the January meeting.
The policy-setting Federal Open Market Committee will hold its final meeting of 2013 on December 17-18.
"The Fed isn't going to tighten (monetary policy) any time soon; they will taper, but only because the economy doesn't need the stimulus anymore," said John Manley, chief equity strategist at Wells Fargo Funds Management in New York.
The Dow Jones industrial average rose 5.33 points or 0.03 percent, to finish at 16,025.53. The S&P 500 gained 3.28 points or 0.18 percent, to end at 1,808.37, a record closing high. The Nasdaq Composite added 6.23 points or 0.15 percent, to close at 4,068.751.
The S&P 500 is up 26.8 percent for the year. The benchmark index is on track for its biggest annual gain in more than a decade.
Twitter's stock closed at its highest level since the company went public in early November. The stock jumped 9.3 percent to end at $49.14 after a spate of product announcements that could boost Twitter's revenue prospects.
Sysco Corp shares climbed 9.7 percent to $37.62 after the food distributor said it would buy rival US Foods for about $3.5 billion and assume about $4.7 billion in debt to create a company with about $65 billion in annual revenue.
In contrast, McDonald's shares fell 1.1 percent to $95.72 after the fast-food restaurant chain reported weaker-than-expected global sales at established restaurants for November. A sharp drop in comparable-store sales in the United States hurt its global sales, McDonald's said.
Shares of Edwards Lifesciences Corp dropped 5.4 percent to $62.73 after the company forecast 2014 earnings below analysts' estimates and said it would face new competition in the United States and Europe.
About 5.6 billion shares changed hands on US exchanges, below the 6.16 billion average so far this month, according to data from BATS Global Markets.
Advancers and decliners were evenly distributed on the New York Stock Exchange. On the Nasdaq, two issues rose for every three that fell.