NEW YORK — The stock market ended higher Monday, but a late fade kept it from closing at an all-time high.

The market marched broadly higher most of the day, helped by optimism about the economy and more corporate mergers, only to slowly lose momentum in the final half hour of trading.

The Standard & Poor’s 500 index ended up 11.36 points, or 0.6 percent, to 1,847.61 — just short of its record close of 1,848.38 set on Jan. 15. The momentum helped the index set a new intraday high of 1,858.76 earlier in the day, however.

The Dow Jones industrial average rose 103.84 points, or 0.6 percent, to 16,207.14 and the Nasdaq composite rose 29.56 points, or 0.7 percent, to 4,292.97.

Investors had little economic data and corporate earnings to work through, so much of the focus was on another round of corporate deal making.

Chipmaker RF Micro Devices jumped $1.22, or 21 percent, to $7.03 after it said would buy TriQuint Semiconductor in an all-stock deal valued at about $1.56 billion. TriQuint soared $2.41, or 26 percent, to $11.64.

Meanwhile, men’s clothing chain Jos. A. Bank rose $4.99, or 9 percent, to $60.04 after competitor Men’s Wearhouse increased its buyout offer. Men’s Wearhouse rose $3.40, or 8 percent, $48.51.

Last week, Forest Laboratories and Actavis announced a $25 billion merger and Facebook said it was buying WhatsApp for $19 billion. That’s on top of deals or offers announced this week.

Companies buying competitors, or buying up a company whose product interests them, should be seen as a positive for stocks, market watchers say.

“It shows that companies still see value in this market, even at these highs,” said Quincy Krosby, a market strategist at Prudential Financial.

In the last 21/2 weeks, the stock market has basically erased of the losses it experienced after a difficult start to the year.

The S&P 500 index was down as much 6 percent for the year as of Feb. 3, as investors worried about emerging markets like China and Turkey. The U.S. economic recovery was also showing signs of slowing growth.

But the U.S. stock market has recovered as turbulence in overseas markets calms down.

In the latest development, the chaos in Ukraine came to an abrupt halt over the weekend following the ouster of President Viktor Yanulovych.