President Trump’s move fulfills a major goal of the chipmaker. But the move faces opposition in Washington — and uncertainty in Beijing.

© Pete Marovich for The New York Times

President Trump’s move fulfills a major goal of the chipmaker. But the move faces opposition in Washington — and uncertainty in Beijing.

The departure of the senior stock picker was one of several leadership changes ahead of Mr. Buffett’s planned departure as chief executive of Berkshire Hathaway.

© Brian Losness/Reuters

President Trump said the acquisition “could be a problem,” suggesting he will insert himself into the regulatory review of the transaction.

© Valerie Plesch for The New York Times

Anthropic, the artificial intelligence start-up, said that Chinese state-sponsored hackers used its tools in a widespread attack.

The highly anticipated event covered a lot of ground on tariff and trade barriers, but questions remain about reaching a lasting accord.

Investors sent major global indexes higher on optimism that President Trump and China’s top leader, Xi Jinping, could reach a wider agreement this week.

Washington and Beijing both need a trade win as steep new tariffs and tough import limits on critical minerals loom.