Analysis
Getting into Anthropic's cap table on the secondary market now takes a lot more capital than getting into OpenAI's, Fortune reported:
- Anthropic minimum check -- at least $25 million, with $50 million-plus typical
- Anthropic secondary valuation -- brokers estimate around $1.4 trillion
- OpenAI minimum check -- as small as $500,000 to $1 million
A Supply-and-Demand Story, Not a Quality Signal
Underline Capital GP Clara Vydyanath put the Anthropic floor plainly: "I think below $25 million is difficult," with $50 million-plus now typical at valuations clearing $1.3 to $1.4 trillion. That gap with OpenAI doesn't reflect brokers or investors rating one company more valuable per share than the other -- it reflects how tightly each company controls who gets onto its cap table in the first place. Anthropic has deliberately tightened its process for admitting new secondary buyers, and Christine Healey of Healey IPO estimates demand outweighs available supply by three to five times at current prices. When a company restricts supply that hard, minimum check sizes rise mechanically as brokers ration scarce allocation toward the largest, most committed buyers rather than spreading smaller checks across more investors.
The Contrarian Read Worth Sitting With
Vydyanath's own assessment cuts against the pricing her market has set: "OpenAI feels underpriced and Anthropic feels overpriced." That's a notable thing for a broker actively facilitating both markets to say publicly, and it's worth more attention than the headline check-size gap, precisely because it comes from someone with no obvious incentive to talk down the asset commanding the bigger fees. If Vydyanath is right, the $25 million floor on Anthropic isn't evidence the company deserves a premium -- it's evidence that artificial scarcity, not fundamentals, is setting the clearing price on a market with no public float to arbitrage against.
The New Infrastructure Around Pre-IPO AI Shares
None of this trading happens through public exchanges -- it runs through a specific new layer of infrastructure: platforms like Caplight (run by CEO Javier Avalos) that aggregate private-market pricing data, brokers like Healey IPO that source and place blocks, and cap-table GPs like Underline Capital that warehouse positions of $20 million to $100 million and sell them down incrementally. That infrastructure barely existed at this scale two years ago, and its growth is itself a signal of how much capital wants exposure to pre-IPO AI labs specifically, independent of which lab.
Why the Gap Matters Heading Into Actual IPOs
Both companies are confidentially preparing to list, Anthropic having filed with the SEC on June 1 and OpenAI a week later. The secondary-market pricing gap -- Anthropic scarce and expensive to access, OpenAI comparatively liquid and cheap to enter -- will collide with public price discovery once either company actually lists, at which point a real float replaces broker-rationed allocation. If Vydyanath's contrarian read holds and Anthropic really is priced ahead of where liquid public markets would set it, that's the specific risk anyone holding secondary Anthropic paper into an actual IPO needs to underwrite -- a listing that reprices the stock down from its private-market scarcity premium, rather than up.
