Anthropic was open about its confidential S-1 filing on Monday.
The $965 billion AI juggernaut announced the filing—which we cannot yet see—on its blog. It’s a contradiction, but then Anthropic is its own kind of contradiction, a still-young private company we know quite a lot about.
The nearly trillion-dollar startup (if it can be called such a thing) has gotten so big that it’s hard to hide in the markets the way a growth-spurting elephant is hard to hide in a zoo. The company—founded in 2021 and helmed by siblings Dario and Daniela Amodei—has seen a historic rise. Back when our AI editor Jeremy Kahn wrote his Fortune cover story on Anthropic in December 2025, the company was valued at $183 billion. One prophetic section:
[Dario] thinks Anthropic could surpass OpenAI as the world’s largest AI company by revenue. “I would argue it’s maybe even the most likely world in which our revenue passes theirs a year from now,” he says. Then he pauses before adding, “I think I’d rather have the largest revenue than the largest data center, because one is black [on an income statement], and the other is red. Again, things I’ve had to learn about business: It’s better to make money than just to lose money.
