U.S. stocks rose, extending a quarterly advance, amid corporate mergers and optimism central banks will support global growth.

The Standard & Poor’s 500 Index advanced 1.2 percent to 2,086.22 at 4 p.m. in New York, maintaining its longest streak of quarterly increases since 1998. With a 0.2 percent advance on Friday, the index completed its first back-to-back gain after 28 days, the longest drought since 1994.

“There was the China central bank comment about stimulus overnight, the economic news this morning was a little bit mixed, and it seems people are putting cash to work thinking maybe earnings are going to come in better than expected,” Larry Peruzzi, the Boston-based director of international trading at Cabrera Capital Markets LLC, said by phone. “The biggest thing in today’s market is there’s no huge negative.”

Federal Reserve Chair Janet Yellen said Friday that the central bank will probably raise rates this year, with subsequent increases taking place gradually, without following a predictable path. China’s central bank chief said the government can do more to support growth in the world’s second-largest economy.

First-quarter profits for S&P 500 companies are forecast to decline for the first time since 2009. Companies will see a contraction of 5.8 percent for the three-month period, according to economist estimates compiled by Bloomberg. Earnings growth forecasts for the quarter were positive as recently as January, the data show.

Data Watch

Consumer purchases rose less than projected in February, indicating the biggest part of the U.S. economy will find it hard to sustain momentum after the best quarter since 2006. Adjusted for inflation, spending declined for the first time in almost a year. Incomes climbed 0.4 percent in February for a second month, propelled by a jump in dividends.

A separate report showed more Americans than forecast signed contracts to purchase previously owned homes in February, indicating a pickup in the housing market ahead of the spring selling season. The index of pending sales increased to the highest since June 2013. An S&P gauge of homebuilder stocks added 1.7 percent to its highest since June 2007.

The U.S. economy grew at a slower pace in the fourth quarter than economists had estimated, a Commerce Department update showed on Friday.

Other reports this week may show the Institute for Supply Management’s manufacturing gauge slipped in March, while payrolls rose at a slower pace.