SA国际传媒

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

The past week brought a varied assortment of large startup financings, with big rounds in sectors ranging from events-based betting to AI to energy to biotech. Leading the pack for round size were prediction market platform and open standards-focused AI startup , which each raised $2 billion.

1. (tied) , $2B, prediction market: , the operator of clearing houses and exchanges including the , that it will invest up to $2 billion into the prediction market platform Polymarket. The deal sets an $8 billion pre-money valuation for New York-based Polymarket, which lets users wager on event probabilities across markets, politics, sports and other areas.

1. (tied) , $2B, AI: New York鈥檚 Reflection AI, a developer of LLM training models based on open standards, raised $2 billion in a backed by and a long list of venture investors. The financing sets an $8 billion valuation for Reflection, which is reportedly the valuation it secured just seven months ago.

3. , $1B, battery power: Base Power, an Austin, Texas-based provider of battery-powered home energy, secured $1 billion in Series C funding led by . Founded in 2023, Base has raised $1.3 billion in known funding to date, .

4. , $510M, space tech: Stoke Space, a developer of reusable launch vehicles, picked up $510 million in Series D funding led by in conjunction with a $100 million debt facility led by . The funding will be used toward expanding production capacity in its launch vehicle and activating its launch complex at Cape Canaveral.

5. , $165M, biotech: San Francisco-based Expedition Therapeutics, a developer of therapies for inflammatory and respiratory diseases, closed on $165 million in Series A funding co-led by and . Funding will support a Phase 2 study for its drug candidate to treat chronic obstructive pulmonary disease.

6. , $150M, legal tech: EvenUp, a legal tech startup that creates artificial intelligence products for the personal injury sector, landed $150 million in Series E funding. Repeat backer led the round, which sets a valuation of more than $2 billion for the San Francisco-based startup.

7. , $130M, health benefits: Minneapolis-based Duos, a digital health platform focused on Medicare beneficiaries, locked up $130 million in a growth equity investment led by . Founded in 2020, Duos has raised over $160 million in known funding to date.

8. , $101M, biotech: Nilo Therapeutics, a startup focused on developing therapies based on advances in neuro-immunology, launched with a $101 million Series A round. , and led the financing for the New York-based company.

9. , $96M, biotech: Torl Biotherapeutics, a startup focused on antibody-based immunotherapies for cancer patients, closed on a $96 million Series C round. The Los Angeles company did not disclose investors but did say the funding would go to advance multiple clinical trials in progress.

10. , $59M, legal tech: Harvey, a provider of AI-enabled tools for legal professionals, raised $59 million from aimed at supporting international expansion. The financing brings total reported funding to date for San Francisco-based Harvey to $865 million, with most of that secured in 2025.

Methodology

We tracked the largest announced rounds in the SA国际传媒 database that were raised by U.S.-based companies for the period of Oct. 4-10. 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.

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