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This is a weekly feature that runs down the week’s top 10 announced funding rounds in the U.S. Check out last week’s biggest funding rounds here.

It may feel like the doldrums of summer, but this past week was nonetheless a pretty action-packed one for big funding rounds. The headliner was Mira Murati’s Thinking Machines Lab, which reportedly snagged $2 billion in a deal that set a record for seed round size. Other AI players, including medical note-taking tool Abridge, and legal tech startup Harvey, also closed large financings.

1. Thinking Machines Lab, $2B, AI: San Francisco-based Thinking Machines Lab, the artificial intelligence startup launched and led by former OpenAI CTO Mira Murati, reportedly secured a $2 billion seed round at a $10 billion valuation with Andreessen Horowitz as lead investor. The financing ranks as the largest U.S. seed round of all time, per Crunchbase data.

2. (tied) Abridge, $300M, healthcare AI: Abridge, a startup that offers an AI note-taking tool for doctors, raised $300 million at a $5.3 billion valuation. Andreessen Horowitz led the Series E financing for the 7-year-old, Pittsburgh- and San Francisco-based company, and was joined by Khosla Ventures.

2. (tied) Harvey, $300M, legal tech: San Francisco-based Harvey, a provider of AI-enabled tools for legal and professional services, landed $300 million at a $5 billion valuation in a financing co-led by Kleiner Perkins and Coatue. The Series E round brings total funding to date for the 3-year-old company to over $800 million.

4. Kalshi, $185M, predictions market: Kalshi, operator of a platform that enables betting on event outcomes in politics, sports, entertainment and other areas, closed on $185 million in Series C funding. Paradigm led the financing, which sets a $2 billion valuation for the New York-based company.

5. Digital Asset, $135M, blockchain: New York-based Digital Asset, a developer of privacy-enabled blockchain technology, locked up $135 million in a financing led by DRW Venture Capital and Tradeweb Markets. The round brings funding to date for the 11-year-old company to more than $440 million.

6. Decagon, $131M, agentic AI: Decagon, a provider of AI agents for customer service, raised $131 million in Series C funding at a $1.5 billion valuation. Accel and Andreessen Horowitz led the financing.

7. Neuron23, $96.5M, biotech: South San Francisco, California-based Neuron23, a developer of precision medicines for genetically defined neurological and immunological diseases, picked up $96.5 million in a Series D round. The company also announced the first patient has been dosed in a Phase 2 clinical trial of a treatment for early Parkinson’s disease.

8. Xona Space Systems, $92M, spacetech: Xona Space Systems, a developer of Low Earth Orbit satellites for navigation, announced $92 million new funding. The fundraise 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, $75M, cybersecurity: Seattle-based XBow, developer of an autonomous AI-driven penetration testing system, secured $75 million in a Series B round financing led by Altimeter Capital. Earlier this year, the startup said it became the top U.S. hacker on HackerOne’s rankings.

10. Ledgebrook, $65M, insurance: Ledgebrook, a Boston-based provider of general liability and professional liability insurance products, raised a $65 million Series C funding round led by The Stephens Group. The financing brings total funding to date to around $115 million, per Crunchbase data.

Methodology

We tracked the largest announced rounds in the Crunchbase database that were raised by U.S.-based companies for the seven-day period of June 21-27. Although most announced rounds are represented in the database, there could be a small time lag as some rounds are reported late in the week.

Illustration: Dom Guzman