Stocks gave up early gains and turned mixed in afternoon trading on Wall Street Thursday as markets struggle to settle down following several days of whiplash moves.

Investors were encouraged to see strong figures for U.S. economic growth, which showed the biggest climb in GDP last year since 1984. Markets are still processing the latest indications from the Federal Reserve a day earlier that the central bank is increasingly concerned about inflation and plans to raise interest rates and take other steps soon to fight it.

The S&P 500 index rose 0.1% as of 1:01 p.m. Eastern. The Dow Jones Industrial Average rose 129 points, or 0.4%, to 34,297 and the Nasdaq fell 0.2%.

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