NVIDIA Corp. (NASDAQ:NVDA), Meta Platforms (NASDAQ:META) and Microsoft Corp. (NASDAQ:MSFT) led 25 companies Friday in signing a letter urging Washington to protect open-weight AI models.

The letter, titled “Open Weights and American AI Leadership,” argues U.S. leadership will be judged not by any single frontier model but by whether the country builds an open ecosystem, and warns that restricting open models would concentrate the technology among a few providers. Signatories also include Palantir (NASDAQ:PLTR), IBM (NYSE:IBM) and Dell (NYSE:DELL)

Alphabet Inc. (NASDAQ:GOOGL) and Amazon.com Inc. (NASDAQ:AMZN) did not sign. Neither did OpenAI or Anthropic, which, according to CNBC, have been lobbying Washington for tighter restrictions on Chinese open-source models, arguing that once powerful models are released openly they cannot be controlled and may be exploited by adversaries.

The Fight That Preceded the Letter

The spark came July 16, when Beijing-based Moonshot AI released Kimi K3, an open-weight model that reportedly performed near the frontier and rattled chip stocks.

Days later, OpenAI strategy chief Dean Ball predicted on X that Washington would create “regulatory risk” around Chinese open-weight models, comments widely read as endorsing a fear-and-doubt campaign against open AI. Ball later walked back parts of the post.

Former White House AI czar David Sacks called it a “weaponization of regulatory uncertainty” and accused the leading closed labs, a revenue duopoly in his description, of wanting the government to eliminate their open-source competition.

Friday’s letter reads as the industry’s answer to Ball. It also wades into the distillation fight, defending the practice of using one model’s outputs to train another as a decades-old development technique. OpenAI and Anthropic have reportedly complained that Chinese labs used distillation to copy their models.

Jensen’s First Post, Altman’s Curious Reply

Nvidia CEO Jensen Huang amplified the letter backing open models in what he said was his first-ever post on X, writing that open models “strengthen safety and cybersecurity, accelerate innovation and diffusion, and enable sovereignty.”

OpenAI CEO Sam Altman replied that he wants the U.S. to win in AI “both in open source and proprietary models” and was “glad to see this,” an endorsement of a letter his own company did not sign.

Polymarket traders give Anthropic a 63% chance of having the best model by the end of the year. Google is in 2nd, with 11%, OpenAI in 3rd with 9%, and xAI in 4th with 3%.

Restrictions on open-weight models would likely protect the labs selling access to the best closed ones, a dynamic Sacks himself flagged when he described the closed labs as a duopoly. Nvidia and Meta, meanwhile, may profit most from a world where open models spread demand across the entire market.

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