25 American Companies Sign Joint Letter Opposing Restrictions on Open-Weight Models; OpenAI Among Non-Participants

Around July 25, 2026, 25 U.S. technology companies issued a joint letter urging policymakers to avoid imposing premature restrictions on open-weight models. The letter was signed by Nvidia, Microsoft, Meta, Dell Technologies, IBM, Palantir, Mistral, Mozilla, Linux Foundation, Hugging Face, Andreessen Horowitz, and Y Combinator, among others. Its core demand is to prevent measures that could stifle competition or drive innovation overseas.

Factual Restoration

The joint letter is titled "Open Weights and American AI Leadership." It notes that open-weight models allow users to download, modify, and run them on their own infrastructure. Moonshot AI's Kimi K3 model has surpassed leading U.S. solutions in multiple industry benchmarks, previously sparking discussions among U.S. officials regarding intellectual property issues. OpenAI, Anthropic, and Google did not join the signatories. Nvidia CEO Jensen Huang posted on social media in support of the letter, while Microsoft CEO Satya Nadella reposted it, emphasizing its role in protecting national security. Elon Musk expressed full support, but SpaceX did not formally sign.

Mechanism Breakdown

The joint letter draws an analogy to the open-source software movement of the 1980s, arguing that the open ecosystem once solidified U.S. technological dominance. It argues that relying solely on closed models is not inherently secure, as they can be compromised or fail in ways undetectable from the outside. Concentrating cutting-edge capabilities in a few closed models creates a single point of failure risk. Techniques such as distillation are described as standard machine learning methods, and restrictions could harm the U.S. AI ecosystem. The letter directly responds to statements by U.S. Treasury officials regarding potential intellectual property issues from Chinese companies, arguing that banning open-weight models is not the optimal path.

Industry Impact

For developers, open-weight models lower the barrier to entry, allowing startups and researchers to build applications on top of existing models rather than training from scratch. For enterprise users, models can be deployed locally, reducing dependence on a single vendor and potentially enhancing data sovereignty. For hardware vendors such as Nvidia, open models may expand chip demand as more entities need computing power to run and fine-tune them. For the closed-model camp, the absence of OpenAI and Anthropic indicates their business models rely more on proprietary control, and during IPO preparation they may prioritize intellectual property protection over broad sharing.

Comparison and Precedents

The joint letter cites the history of open-source software in the 1980s; the involvement of Mozilla and Linux Foundation reinforces this continuity. The current debate has shifted from technical performance to policy, echoing previous U.S. export controls on Chinese chips, but this time directly involving model weights rather than hardware.

Strategic Assessment

Based on the composition of existing signatories and the list of absent parties, the most likely scenario is that policymakers will weigh the balance between the competitive advantages of openness and security concerns.