A San Francisco start-up called Arena found that people are most likely to use A.I. agents on the job, particularly if they are in the tech industry.

The $135 share price means Elon Musk’s rocket maker is poised to exceed the 2019 initial public offering of Saudi Aramco in both valuation and money raised.

Anthropic raised $65 billion in new fund-raising that put its value at $900 billion, ahead of OpenAI’s last valuation of $730 billion, as the companies duel for A.I. dominance.

A Mad Hatter and a giant rabbit sit around a table discussing an A.I. start-up. This is normal behavior around the Bay Area these days.

The dream of clean hydrogen has tantalized energy experts for years, but producing it has been tough. Many start-ups think the answer could lie beneath our feet.