Anthropic's Fable shutdown is a big moment for open-source AI

In this photo illustration, the Anthropic logo is seen on a smartphone with a Claude Mythos logo in the background. Sopa Images | Lightrocket | Getty Images Anthropic's suspension of its top AI models late last week drove home a hard truth for the companies that were counting on them: access can be cut off at any time. It's been a big theme this week, and one that Wall Street will be watching closely as Anthropic and OpenAI gear up for potentially massive IPOs in the coming months. Microsoft CEO Satya Nadella is warning of the risks, even as his company is the principal investor in OpenAI, and backed Anthropic last year to the tune of billions of dollars. He wrote Monday in a post on X that companies need to "build agentic systems that improve over time, while still retaining control over their IP." "The last thing any of us want is a world where every company across every sector is ceding value to a few models that eat everything they see," Nadella wrote. Investors have been trading on that theme. MiniMax and Zhipu , the Chinese open-source AI lab, both surged on Monday as the Anthropic fight put a spotlight on downloadable models that companies can run themselves. The Anthropic-Fable news landed at an awkward moment late Friday. Roughly two hours earlier, SpaceX had wrapped up its first day of trading following the biggest IPO on record. SpaceX's xAI unit is a niche player in artificial intelligence, but CEO Elon Musk is an outspoken voice on the topic. …