Thinking Machines Lab Leads Record Week for U.S. Startup Funding

By Nathan Brooks

Thinking Machines Lab reportedly secured a $2 billion seed round at a $10 billion valuation, the largest U.S. seed round of all time, according to Crunchbase data. Andreessen Horowitz led the financing, Crunchbase reported. The San Francisco startup was launched and is led by former OpenAI CTO Mira Murati.

At $2 billion, the financing was more than six times the $300 million raised by Abridge and Harvey. It reset the reference point for seed capital and showed how sharply the week’s funding concentrated at the top.

Crunchbase’s weekly ranking covered the ten largest announced funding rounds at U.S.-based companies. Thinking Machines Lab led the list; the other nine were:

• 2 (tie) — Abridge: $300 million. According to Crunchbase data, the seven-year-old Pittsburgh and San Francisco startup raised a Series E at a $5.3 billion valuation. Andreessen Horowitz led the round, and Khosla Ventures joined. Abridge offers an AI note-taking tool for doctors.

• 2 (tie) — Harvey: $300 million. According to Crunchbase data, Harvey raised a Series E at a $5 billion valuation. Kleiner Perkins and Coatue co-led the round, lifting the three-year-old San Francisco company’s total funding to more than $800 million. Harvey provides AI-enabled tools for legal and professional services.

• 4 — Kalshi: $185 million. According to Crunchbase data, Kalshi raised Series C funding at a $2 billion valuation. Paradigm led the financing for the New York predictions-market operator. Its platform enables betting on event outcomes in politics, sports, entertainment and other areas.

• 5 — Digital Asset: $135 million. According to Crunchbase data, the 11-year-old New York company raised a financing led by DRW Venture Capital and Tradeweb Markets. Digital Asset develops privacy-enabled blockchain technology. The round lifted its total funding to more than $440 million.

6 — Decagon: $131 million. According to Crunchbase data, Decagon raised Series C funding at a $1.5 billion valuation. Accel and Andreessen Horowitz led the round. Decagon provides AI agents for customer service.

7 — Neuron23: $96.5 million. According to Crunchbase data, Neuron23 raised a Series D round. The South San Francisco, California-based company develops precision medicines for genetically defined neurological and immunological diseases. It also dosed the first patient in a Phase 2 clinical trial of a treatment for early Parkinson’s disease.

8 — Xona Space Systems: $92 million. According to Crunchbase data, Xona Space Systems raised new funding for its Low Earth Orbit navigation satellites. The financing includes a $72 million Series B led by Craft Ventures and another $20 million from SpaceWerx, the innovation arm of the United States Space Force.

9 — XBow: $75 million. According to Crunchbase data, XBow raised a Series B round led by Altimeter Capital. The Seattle startup develops an autonomous, AI-driven penetration-testing system. Earlier this year, the startup said it became the top U.S. hacker on HackerOne’s rankings.

10 — Ledgebrook: $65 million. According to Crunchbase data, Ledgebrook raised a Series C round led by The Stephens Group. The Boston company provides general liability and professional liability insurance products. The financing brought total funding to around $115 million.

Crunchbase tracked the largest announced rounds in its database for U.S.-based companies over the seven-day period from June 21 to June 27, 2025. Most announcements were represented, but Crunchbase warned that rounds reported late in the week could enter later because of a small time lag.

What does this change for founders and investors?

Crunchbase’s price ladder gives founders a concrete benchmark by stage and use case. Thinking Machines Lab reached a $10 billion valuation in seed financing, Abridge and Harvey reached $5.3 billion and $5 billion after $300 million rounds, and Decagon reached $1.5 billion with $131 million.

For investors, AI still dominated the list, with five of the 10 companies explicitly selling AI products. Yet the competitive field widened beyond AI itself. Prediction markets, privacy-enabled blockchain, precision medicines, navigation satellites, penetration testing and liability insurance all joined the capital table.

That mix changes the practical pitch. An AI label offers little valuation guidance on its own; the relevant comparison is medical note-taking at $5.3 billion, legal AI at $5 billion, or customer-service agents at $1.5 billion.

The concentration also raises the execution bar. The next test is whether another seed company can approach Thinking Machines Lab’s $10 billion valuation, or whether the record remains an outlier while $300 million rounds become the repeatable benchmark for AI applications.