Stocks took off across the board Monday as concerns over a trade war abated. (Michael Nagle/Bloomberg News)

Stocks sailed to a strong finish Monday as concerns over a trade war abated.

The Dow Jones industrial average climbed 669 points, or 2.8 percent, and closed at 24,202.60 as the markets took a deep breath — then exhaled — over concerns that a trade mess would end a global economic boom.

The Standard & Poor’s 500-stock index gained 2.7 percent, closing at 2,658.55. Even the tech-heavy Nasdaq composite index, beleaguered last week over data privacy issues at its go-to winner Facebook, surged 3.3 percent to 7,220.54. Across the board, it was the best day for the markets since 2015.

The boomerang came after statements by Treasury Secretary Steven Mnuchin that he was optimistic that the United States and China could avert a trade war.

President Trump last week announced his intention to impose at least $60 billion in tariffs on Chinese imports into the United States. China in turn signaled that it planned to tax some U.S. goods sold in that country. The back-and-forth sent stocks tumbling to one of their worst weeks in years.

“We’re having very productive conversations with them,” Mnuchin said on “Fox News Sunday,” referring to China. “I’m cautiously hopeful we reach an agreement.”

Other Trump administration spokesmen headed to the airwaves Monday to calm markets and tout the administration’s efforts to rework trade deals with China and with the United States’ North American trading partners, Mexico and Canada.

Trump trade czar Peter Navarro appeared on CNBC’s “Squawk Alley,” where he bolstered U.S. efforts to renegotiate the North American Free Trade Agreement. Just weeks ago, it looked as if NAFTA might be dead.

“It looks like we might get a really good deal on NAFTA,” Navarro said.

In a tweet Monday, the president hailed the economy as “looking really good. It has been many years that we have seen these kind of numbers.”

Among the leaders in the blue-chip Dow on Monday were several technology plays, including Microsoft, Intel, Apple and United Technologies. General Electric was the only laggard in the Dow, down more than 1 percent.

U.S. stock markets are coming off their worst week in more than two years.

The Dow plummeted in the final hours of a bouncy day Friday and closed down 424 points, or 1.77 percent. The Dow shed 1,100 points in the last two trading days of last week.

“It’s the old ‘sell on the news’ and then regroup,” said Daniel P. Wiener, chief executive officer of Adviser Investments, a Newton, Mass.-based firm that manages more than $5 billion in assets. “We had the weekend to regroup. It remains to be seen how far President Trump will go with these tariffs . . . and whether cooler heads are going to help him negotiate and navigate the no-compromise $60 billion comment he made last week. He has already backed off the blanket 25 and 10 percent tariffs on steel and aluminum.”

Despite the Nasdaq’s rebound, Facebook struggled Monday as the social media powerhouse, with more than 2 billion monthly users, reeled from a crisis over data misuse. The Federal Trade Commission on Monday announced it is investigating the company following reports that Cambridge Analytica leak of information on 50 million users. Facebook is about 20 percent off its 52-week high.

The Dow appeared to be climbing out of correction territory. At the close of trading Friday, the 30-member bellwether was down more than 10 percent from its Jan. 26 peak. A 10 percent decline from a recent high is considered a correction.

The Dow is still on pace for one of its worst-performing months since 2015 as investors grow anxious that Trump’s trade policies and their fallout could upset a robust global economy. U.S. markets fell swiftly this month when he imposed steep tariffs on steel and aluminum imports.

All 11 sectors of the S&P were in positive territory Monday. Financial services, information technology and consumer staples were leading the way. The big gainers were Lowe’s home repair retail stores, Microsoft and Intel.

“This is a relief rally in tech shares that may not suffer from strained dealings with China as much as feared last week,” Washington investment manager Michael Farr said. “Tech was hammered hardest last week and is bouncing highest today.”

The S&P 500 is down 0.6 percent this year, while the Nasdaq composite is up 4.6 percent.

The U.S. economy is in good shape, helped by the fiscal stimulus in the recent Republican-backed tax cuts, the repatriation of tens of billions in corporate profits and a massive budget Trump signed last week that includes vast increases in military spending.