U.S. stock index futures ticked higher Tuesday after a housing report that showed home prices rose in July, but gains were limited as investors digested some mixed messages from Federal Reserve officials on the future of the central bank's stimulus program.
Home prices climbed 0.6 percent in July, according to the S&P/Case-Shiller composite index of 20 metropolitan areas. Compared to a year earlier, prices were up 12.4 percent, matching economists' expectations and marking the strongest rise since February 2006.
"The recovery in housing has been an important source of support for the U.S. economy, with residential investment adding to real GDP (gross domestic product) growth for eight consecutive quarters," said Barclays analysts Hamish Pepper and Cagdas Aksu in a note on Monday.
Consumer confidence for September is expected at 10 am ET.
In a busy week for speeches by Fed officials, New York Fed President William Dudley and Atlanta Fed President Dennis Lockhart took a dovish tone at the start of the week. Dudley said he supported the Fed's surprise decision to delay scaling back its monthly $85 billion bond-buying program, given the lack of momentum in the U.S. economy.
Dallas Fed President Richard Fisher, however, was more hawkish, indicating that he would have opposed the inaction if he had a vote.
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On Tuesday, investors will eye comments from Kansas City Fed President Esther George, who is due to speak at 12:30 p.m. ET. Last week, she said the Federal Reserve created confusion in the market with its lack of decision to taper. Cleveland Fed President Sandra Pianalto is also scheduled to make a speech on Tuesday.
Investec analyst described the "Fed flustering" as a "very bad one-sided baseball game."
"Bernanke threw a massive curveball with a surprise no taper on Wednesday saying any scale back would be data dependent," the analysts wrote in a note on Tuesday. "(On Monday) it was Dudley and Fisher off the benches, throwing dovish and hawkish fastballs just to confuse us all a bit more. The world series of mixed messages isn't over quite yet however, we have nine more Fed speakers on the mound before the week is out."
(Read more: Fisher: Fed selection process 'terribly' mishandled)
Among earnings, Lennar advanced after the homebuilder posted better-than-expected earnings as it sold more homes at higher prices.
Facebook edged higher after Citi upgraded the social-networking giant to "buy" from "neutral," citing the sustainability of recent increases in growth even amid initial uncertainty about an increasing shift to mobile use. Separately, Facebook rolled out its new "Autofill" mobile payments product, according to tech news website AllThingsD.
Apple climbed after at least four brokerages lifted their price targets on the tech giant. On Monday, Apple said that sales for its new iPhone had set a record, with consumers snapping up nine million smartphones within the first few days of its launch.
Concerns over the debt ceiling also looked set to weigh on Tuesday, with trading expected to be choppy ahead of the October 1 deadline for Congress to pass a resolution to keep the government funded. If a deal is not struck, it could force a partial shutdown of the government.
This uncertainty out of the U.S. weighed in Asia, amid a lack of market catalysts, sending stocks lower on Tuesday. The Shanghai Composite, Australia's S&P ASX 200 and South Korea's Kospi all posted modest losses while Japan's Nikkei and India's benchmark index were flat.
In Europe, however, stocks held modest gains in mid-morning trade on Tuesday, with technology companies leading the way. The pan-European FTSEurofirst 300 Index was slightly higher after the release of German business sentiment, which showed a rise in September - but fell short of analysts' expectations.
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In the debt market, meanwhile, the Treasury is expected to sell $33 billion of two-year notes on Tuesday.