After DeepSeek Upended the Market, Is It Worth Investing in A.I.?

After the arrival of a less costly A.I. model from China, U.S. markets and academics are wrestling with the ultimate economic value of the technology.

As Elon Musk Embraces the Far Right, Some of Its Leaders Reject Him

Mr. Musk has fallen out with prominent right-wing Americans who say they are worried that their agenda may be sidelined in favor of his own — and that he is willing to silence them on X.

How Trump Could Upend Electric Car Sales

Fewer people will be able to afford electric cars and trucks if President-elect Donald J. Trump and Republicans in Congress eliminate a $7,500 federal tax credit.

How Elon Musk Cuts Costs at Tesla, SpaceX and X

Mr. Musk dug into his companies’ budgets, preferring to cut too much rather than too little and to deal with the fallout later. Under Donald Trump, he is set to apply those tactics to the U.S. government.

Jeff Bezos, Elon Musk and the Billions of Ways to Influence an Election

The world’s richest men have their own rocket fleets, their own media and their own schemes to succeed with Donald J. Trump.

Why GM’s Mary Barra Still Believes in EVs, Despite Slow Sales

Mary Barra, G.M.’s chief executive, said that the company had fixed battery-manufacturing problems and that its electric vehicles would soon be profitable.

How Elon Musk’s Security Detail Has Grown Following Death Threats and Stalkers

As threats to his personal safety have become graver, the world’s richest man has barricaded himself behind a phalanx of bodyguards that operates like a mini-Secret Service.

How Elon Musk Is Influencing Donald Trump

Their fast-evolving political friendship has become a potential minefield, as Mr. Musk’s sprawling businesses may present conflicts of interest if Mr. Trump is elected in November.

Tesla Q2 Earnings Report Reveals 45% Profit Drop Amid Weak E.V. Sales

The company led by Elon Musk is selling fewer electric cars, and its big bets on driverless taxis and artificial intelligence could take many years to pay off.