By Anora Mahmudova and Barbara Kollmeyer, MarketWatch

Core consumer prices rise 0.3% in April

U.S. stocks struggled to push higher after a stronger-than-expected reading of a measure of price inflation, but the main indexes were still on track to post modest weekly gains.

An increase in the consumer-price index along with the improving labor market offers the Federal Reserve reserve ammunition to raise interest rates sooner than later, even as minutes from the most recent meeting of the Federal Open Market Committee suggested that a June rate hike was unlikely.

Investors also are awaiting a speech from Federal Reserve Chairwoman Janet Yellen on the economic outlook to the Greater Providence Chamber of Commerce at 1 p.m. Eastern Time ahead of a long holiday weekend. Read a preview (http://www.marketwatch.com/story/why-consumers-are-so-cautious-2015-05-19).

The S&P 500 (SPX) was about flat at 2,130.70. The Dow Jones Industrial Average (DJI) was off by 13 points, or 0.1%, to 18,272, while the Nasdaq Composite (RIXF) was up 11 points, or 0.2%, to 5,101.89, trading above its previous record close, reached on April 24.

Maris Ogg, president at Tower Bridge Advisors, said that the market is climbing the wall of worry and looking ahead to better earnings next year.

"The second half of this year will show us whether housing and capital expenditures really pick up and whether that will drive earnings in 2016," Ogg said.

Ogg noted that the market is digesting the possibility of a rate hike this year pretty well. "At this point investors know that a rate increase means an improving economy. A 25 or 50 basis point increase will not affect the companies or the economy much and starting from zero means it will take a while before rates start having a negative effect on markets," Ogg said.

As long as bond yields are moving sideways or lower, equity investors are "happy putting money to work," said Chris Weston, chief market strategist at IG, in a note. He added that the CBOE Volatility index (VIX) is testing the year's lows around 12.11%, and is now 33% below the five-year average.

Friday could remain a quiet day for Wall Street if many traders take off early for the Memorial Day holiday, which will see markets closed on Monday.

U.S. consumer prices (http://www.marketwatch.com/story/housing-healthcare-behind-strong-rise-in-core-inflation-in-april-2015-05-22) rose a seasonally adjusted 0.1% in April, according to the Labor Department. Energy prices slumped 1.3% last month while food prices were unchanged. The core CPI, which excludes volatile food and energy costs, jumped 0.3%, driven by another increase in housing expenses and a gain in medical care costs.

In corporates, (http://www.marketwatch.com/story/why-consumers-are-so-cautious-2015-05-19)shares of Deere & Co.(DE) are up 3.7% after financial results. Campbell Soup Co. (CPB) profit beat expectations (http://www.marketwatch.com/story/campbell-soup-profit-beats-views-while-sales-slip-2015-05-22), but sales slipped. Shares rose 2.2%.

Shares of Hewlett-Packard Co.(HPQ) rose 3.3% after earnings squeezed past forecasts late Thursday, but the company also provided a cautious outlook.

Marvell Technology Group Ltd. (MRVL) could see pressure. The chip maker fell more than 2% late Thursday after saying its financial chief will retire.

Expedia Inc.(EXPE) shares jumped 5.3% after the travel booking company said it sold its majority stake in eLong Inc. to a group of buyers for $671 million.

For more on notable movers read Movers & Shakers column (http://www.marketwatch.com/story/campbell-soup-deere-foot-locker-earnings-in-focus-2015-05-21).

Other markets: European stocks were trading slightly lower, while Asia stocks rose with the Shanghai Composite Index (http://www.marketwatch.com/story/china-shares-hit-seven-year-high-2015-05-21) marking its best performance since 2008.

Oil prices (http://www.marketwatch.com/story/oil-holds-onto-recent-gains-wti-trades-above-60-a-barrel-2015-05-22)(CLN5) slipped below $60 a barrel, falling more than 1%, while gold prices (GCM5) gained. The dollar (http://www.marketwatch.com/story/dollar-slips-against-yen-as-investors-await-boj-kuroda-remarks-2015-05-22)(DXY) rose against the euro (EURUSD) and the yen (USDJPY) after the CPI report.

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