The market was recovering from a steep decline the day before.
The Dow Jones industrial average rose 149 points, or 1 per cent, to 15,888 as of noon (1700 GMT) Thursday.
The Standard & Poor's 500 index climbed 22 points, or 1.3 per cent, to 1,796. The Nasdaq jumped 80 points, or 2 per cent, to 4,131.
Facebook rose $8.51, or 16 per cent, to $62.05. The social media company reported results late Wednesday that were better than investors were expecting, thanks partly to growth in mobile advertising revenue.
The government reported that the U.S. economy grew at a 3.2 per cent annual rate in the final three months of last year.