Anthropic has quietly purchased a Dimension-backed stealth startup called Coefficient Bio in a deal worth just over $400 million in stock, according to a letter that I’ve obtained.

The startup was working on AI models for biological research. It was pursuing nothing short of artificial superintelligence for science.

They are joining Anthropic’s Health Care Life Sciences team led by Eric Kauderer-Abrams.

The company, which had stayed under the radar and was formally founded only eight months ago, was half-owned by the venture capital firm Dimension.

Samuel Stanton, one of Coefficient’s co-founders, tweeted in January as part of a recruiting pitch, “We’re ushering biopharma into the Intelligence Age. It will change everything about how the industry learns and makes decisions.”

Dimension is boasting a 38,513% IRR on the investment. (I first broke the news in 2022 that two Lux Capital partners were leaving to join with a partner from Obvious Ventures to found Dimension.)

Dimension and Anthropic declined to comment for the story.

Anthropic’s previous acquisitions include Bun and Vercept.

It’s hard not to marvel at the contrast between Anthropic’s science-forward acquisition and OpenAI’s media-oriented purchase in the headlines today.

I’ve obtained Dimension’s letter to its limited partners. Newcomer subscribers can read it here: