According to Axios, Anthropic declined to sign an open letter led by Nvidia CEO Jensen Huang urging Washington not to restrict open-weight AI models, leaving the Claude maker alone among major frontier labs as Google and OpenAI joined the effort. Anthropic CEO Dario Amodei said in a Monday blog post that the company has never called for banning open models, while arguing that tighter controls are needed on chips and other inputs that could make advanced models dangerous. The company is also navigating disputes over military use, AI safety rules and allegations that Chinese labs trained lower-cost systems on Claude outputs, even as it remains a top-ranked AI lab with a $965 billion valuation in May and is preparing for a potential IPO.