Stocks rallied, giving the Standard & Poor’s 500 Index its biggest four-day gain since September, amid increased optimism Greece will avoid default and after American business activity improved.

Industrial, energy and technology companies led gains in the S&P 500, rising at least 1.4 percent, as investors bought stocks tied to economic growth.

The S&P 500 advanced 1 percent to 1,320.64 at 4 p.m. in New York, rising 4.1 percent in four days. The Dow Jones industrial average gained 152.92 points, or 1.3 percent, to 12,414.34.

“It’s not surprising that the market is rebounding,” said Mike Ryan, the New York-based chief investment strategist at UBS Wealth Management Americas. “The Greece situation will work out, concerns about a soft patch were overdone.”