The tech sector has often been at the center of the economic tug-of-war between Washington and Beijing in recent months. The industry relies on an extensive network of factories in Asia, making it vulnerable to tariffs on Chinese imports.

China is also a major consumer of tech products made by companies like Apple. And the Trump administration’s ban prohibiting American firms from selling technology to the Chinese telecommunications giant Huawei raised the risk that Beijing would retaliate against American tech firms.

On Monday, investors appeared to be shaking off concerns about such risks after President Trump and his Chinese counterpart, Xi Jinping, agreed on Saturday to resume negotiations geared toward resolving a trade war that has spooked markets around the world.

Mr. Trump also agreed to loosen restrictions on the sale of some American technology to Huawei, as long as it did not have national security implications.

The question for investors now is whether the peace will last and a deal that both sides are happy with can be reached, or if talks will break down again.