OpenAI Completes Deal That Values It at $500 Billion

With the agreement, OpenAI becomes the world’s most valuable privately held company, surpassing the rocket maker SpaceX.

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A.I. Fighter Jets and Cockroach Spies: Inside the Changing Business of War

Russia’s war on Ukraine changed the course of a generation of start-ups and investors that have applied a new business model to Europe’s military buildup.

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Top A.I. Researchers Leave OpenAI, Google and Meta for New Start-Up

Founded by a co-creator of ChatGPT, Periodic Labs aims to build artificial intelligence that can accelerate discoveries in physics, chemistry and other fields.

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Would You Work ‘996’? The Hustle Culture Trend Is Taking Hold in Silicon Valley.

The number combination refers to a work schedule — 9 a.m. to 9 p.m., six days a week — that has its origins in China’s hard-charging tech scene.

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Oura Heath’s C.E.O. Knows the Secret to Better Sleep

Oura Health makes a pricey smart ring that busy executives, celebrities and others use to track health measures like their sleep patterns. It expects $1 billion in sales this year.

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Trump’s $100,000 Visa Fee Puts Many Tech Start-Ups in a Bind

Silicon Valley start-ups said they were concerned they would be disproportionately hurt by the new visa fee for skilled foreign workers, given their limited resources.

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Elon Musk Has Focused on xAI Since Leaving Washington

Mr. Musk spent the summer at his artificial intelligence start-up xAI, trying to match the runaway success of OpenAI. The result was chaos.

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Robinhood Unveils a Publicly Traded Venture Capital Fund

The brokerage plans to announce a new publicly traded venture capital fund that would let ordinary investors get a piece of privately held start-ups.

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OpenAI Takes Big Steps Toward Its Long-Planned Reorganization

The start-up reached a tentative deal with Microsoft, its biggest investor, and said it would give a $100 billion stake to the nonprofit that manages it.

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CBS News Weighs Major Role for Bari Weiss as Part of Deal to Buy The Free Press

The talks with Ms. Weiss, a founder of The Free Press, are the strongest sign yet that the new owner of CBS News intends to make major changes.

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