On Wednesday, the Federal Reserve said it was prepared to "increase or reduce" the monthly pace of its $85 billion in bond purchases.
(Read More: Roubini: Fed Risking Sequel to 2008 Financial Crisis)
ING U.S. edged higher in its market debut on the NYSE after the insurance and retirement-savings plan provider priced its IPO at $19.50 a share, below the initial expected range. The company started trading under the ticker symbol "VOYA," and said it plans to rebrand the company as Voya Financial over the next few years.
Among earnings, General Motors rallied after the automaker posted stronger-than-expected earnings.
Facebook jumped more than 5 percent after the social-networking giant posted revenue that exceeded expectations, as the company's mobile ad revenues continued to gain.
Yelp surged more than 25 percent after the consumer-review website reported revenue that beat analysts' estimates and forecast second-quarter revenue above expectations.
SunPower spiked higher an hour ahead of the close after the solar company posted quarterly results that blew past expectations. The company was initially scheduled to post earnings after the closing bell.
Kellogg slipped after the cereal maker reported lower earnings, hurt by higher cost of commodities, but said it was on pace to meet its full-year goals.
AIG, Gilead Sciences and LinkedIn are among notable companies scheduled to post quarterly results after the closing bell.
To date, just over 75 percent of S&P 500 companies have posted quarterly results, with 69 percent topping earnings expectations and 21 percent missing, according to the latest data from Thomson Reuters. If all remaining companies report earnings in line with estimates, earnings will be up 4.8 percent from the same time a year ago.
However, only 46 percent of companies have beaten their revenue forecasts. On average, sales have come in 1 percent below estimates.
Intel announced that its board elected its current COO Brian Krzanich as the next chief executive. Krzanich will assume the role of CEO as of the chipmaker's May 16 shareholder meeting.
Meanwhile in Asia, shares fell across the board after Purchasing Managers' Index (PMI) data showed Chinese factory growth easing, indicating that sluggish demand from the U.S. and Europe is weighing on Chinese exports.
Experts say that these factors, combined with Europe's high unemployment and easing inflation, could trigger a round of monetary stimulus from central banks around the world.
Also on the economic front, the U.S. trade deficit declined more than expected in March as imports posted their biggest decline since 2009, according to the Commerce Department. Separately, U.S. nonfarm productivity rose modestly in the first quarter, according to the Labor Department, while revised figures showed that productivity fell in the fourth quarter.