U.S. stocks surged midday Thursday after President Trump unveiled a major trade agreement with the United Kingdom and signaled potential tariff reductions on Chinese imports, fueling investor optimism over global trade stability.

The Dow Jones Industrial Average rose 588.98 points, or 1.43%, to 41,702.9. The Nasdaq Composite added 329.05 points, or 1.86%, to 18,067.2, while the S&P 500 gained 80.17 points, or 1.42%, to 5,711.45.

The rally came after Mr. Trump announced a bilateral trade pact that eliminates tariffs on British steel and aluminum and expands access for U.S. agricultural goods. The U.K., in turn, agreed to purchase $10 billion worth of boeing aircraft. British car exports to the U.S. will now face a 10% tariff, down from 27.5% previously.

“I’m thrilled to announce that we’ve reached a breakthrough trade deal with the United Kingdom,” Mr. Trump said Thursday from the Oval Office. “The deal includes billions of dollars of increased market access for American exports… virtually all of the products produced by our great farmers,” he said.

Prime Minister Keir Starmer, who joined the event by phone, said the agreement would stimulate job creation and economic growth. “It’s going to not only protect jobs, but create jobs, opening market access,” Mr. Starmer said.

Markets were also buoyed by Mr. Trump’s comments suggesting he is open to reducing tariffs on Chinese goods following a new round of negotiations scheduled for this weekend in Switzerland. He hinted at a possible meeting with Chinese President Xi Jinping, pending the outcome of those talks.

“If that happens, on top of all of these trade deals that we’re doing, this country will hit a point — you better go out and buy stocks now,” Mr. Trump said, referring to a broader global trade breakthrough.

The combination of transatlantic trade progress and a possible thaw in U.S.-China relations lifted investor sentiment. With diplomatic momentum building, analysts say markets may continue to climb as trade policy uncertainty eases.