Among key earnings, Amazon.com gained despite a disappointing first-quarter earnings results released after the bell Tuesday, as the Internet retailer raised its revenue guidance for the second quarter.
Boeing traded flat after beating analyst earnings estimates for its first quarter, but the aircraft maker delivered a disappointing full-year forecast.
And Northrop Grumman gained after reporting a rise in first-quarter profits and revising its full-year guidance upwards. The defense contractors, which makes unmanned spy plans, said its revenue for the quarter fell 3 percent to $6.73 billion.
Several oil companies are reporting earnings this week. In London, BP reported a fall in first-quarter profit as the oil giant's profits continued to suffer from the Gulf of Mexico spill.
ConocoPhillips fell despite a rise in quarterly earnings as the energy company said its production was hurt by the conflict in Libya and by the closure of a pipeline, while Hess soared after reporting a spike in first quarter earnings.
Exxon Mobil reports earnings before the bell on Thursday, while Chevron reports on Friday.
Oil prices, meanwhile, fell after the government reported a jump in oil inventories by 6.2 million barrel, which was more than expected. London Brent crude fell below $124 a barrel, while U.S. light crude fell to just above $112.
In other company news, said it had struck a deal to buy Swiss medical device maker Synthes for $21.3 billion.
And Merck rose slightly after its board approved $5 billion in stock buybacks.
Silver prices firmedafter the biggest one-day slide in a month, as gold rose as the dollar continued to weaken against a basket of currencies.
Barrick Gold traded lower despite reporting a 22 percent gain in first quarter profits thanks to the rising price of gold.
The Treasury's auction of $35 billion in five-year notes came in as expected, with the notes priced at a high yield of 2.124 percent, and a bid-to-cover ratio of 2.77.
On the economic front, new orders for durable goods rose 2.5 percent in March from an upwardly revised 0.7 percent rise in February, according to the Commerce Department. Economists had expected a rise of about 2 percent, Reuters said.
And the Chicago Fed's Midwest Manufacturing Index rose to 85 in March from 83.4 in February.
Also, the Mortgage Bankers Association's index of home loan activityfell 5.6 percent in the week ended April 22. The MBA blamed higher insurance premiums for government-insured loans for hurting demand.
Standard & Poor'scut its rating outlook for Japan to "negative" from "stabe," while affirming the nation's double-A-minus rating, saying the disasters triggered by the earthquake in March would hurt the country’s public finances if taxes aren't raised. Stocks had little reaction to S&P's move, as the Nikkei closed more than 1 percent higher.
On Tap This Week:
WEDNESDAY: Oil inventories, 5-year Treasury note auction; earnings after-the-bell from eBay, Starbucks, Allstate, Baidu, Citrix, Flowserve, and Norfolk Southern.
THURSDAY: GDP, jobless claims, pending home sales, 7-year Treasury note auction; earning before-the-bell from AstraZeneca, Deutsche Bank, Exxon Mobil, PepsiCo, P&G, Royal Dutch Shell, Sanofi-Aventis, Bristol Myers, Discovery Communications, Dow Chemical, Medco Health, Motorola Solutions, Occidental Petroleum, Pulte Group, Raytheon, Sprint Nextel, Starwood, Thomson Reuters, Time Warner Cable, and Viacom, and after-the-bell from Microsoft, Cliffs Natural Resources, and Motorola Mobility.
FRIDAY: Personal income, personal spending, Chicago PMI, Thomson Reuters/University of Michigan consumer sentiment; earnings before-the-bell from Caterpillar, Chevron, Merck, DR Horton, Pitney Bowes, and Weyerhaeuser.
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