"That's the only major thing that's happened," said Dan Greenhaus, chief global strategist for the brokerage BTIG. "It's an excuse to rally the stock market."
Technology stocks and energy companies made the biggest gains. Utility stocks, which tend to do well when investors are fearful, were the only industry group in the S&P to fall.
The market gains started earlier, in Asia, helped by expectations that the People's Bank of China will act soon. China's biggest steelmaker said Thursday it has shut down a mill in Shanghai, a sign of weakening growth.
Stocks rose 0.5 percent in Japan and 1.1 percent in Hong Kong.
Among other U.S. companies making moves:
• Tempur-Pedic International, the mattress company, climbed $3.86, or 14.4 percent, to $30.64 after announcing it would buy a rival, Sealy, for about $229 million in cash.
• Discover Financial Services rose $2.69, or 7.3 percent, to $39.71. It reported a slight earnings decline in its latest quarter but beat Wall Street expectations. It also said credit card use increased and more customers paid off cards on time.• GE hit a four-year high after the company told analysts it expects industrial revenue to rise about 10 percent this year. GE gained 63 cents, or 2.9 percent, to $22.73 in afternoon trading. They rose as high as $22.86.