Key Takeaways
- • US startups raised $27.89B across 754 rounds in September 2026, up 54% from August's $18.1B but 9.8% below September 2025's $30.91B, according to AlleyWatch.
- • Four rounds of $1B or more (Crusoe $3.9B, The Boring Company $3.0B, Cognition $2.0B, Stoke Space $1.0B) totaled $9.90B, or 36% of the month's capital.
- • Late-Stage rounds drew $19.84B, roughly double August's $9.81B, representing 71.2% of September capital.
- • AI infrastructure led sector concentration, with Crusoe, Positron, Gimlet Labs, Celero, GMI Cloud and Cornelis Networks raising $5.78B combined.
- • New York captured $3.14B, or 11.2% of US capital, up from 4.8% in August, while California took $9.58B (34% of total).
Summary
US venture-backed startups raised $27.89B across 754 disclosed rounds in September 2026, according to AlleyWatch's US startup funding data. The total was up 54% from August's $18.1B and down 9.8% from September 2025's $30.91B. Capital was highly concentrated: 53 rounds of $100M or more accounted for $20.81B, or 75% of the month's total.
Four rounds of $1B or more drove a significant share of activity. Crusoe's $3.9B Series F, co-led by Atreides, Mubadala Capital and Valor Equity Partners, topped the month. The Boring Company raised $3.0B in a Series D led by Valor Equity Partners, Sequoia Capital and Andreessen Horowitz, while Cognition raised $2.0B in a Series E and Stoke Space raised $1.0B in a Series E. Those four rounds totaled $9.90B.
By sector, AI infrastructure was the deepest pool. Crusoe, Positron ($875M), Gimlet Labs ($300M), Celero ($275M), GMI Cloud ($223M) and Cornelis Networks ($205M) together raised $5.78B across compute, chips and networking. Software-side AI rounds, including Cognition, Harvey ($550M) and Snorkel AI ($350M), added $2.90B. Space and defense companies Stoke Space, Mach Industries ($600M) and Impulse Space ($308M) raised $1.91B. Health companies led by Enveda ($311M) and Encoded Therapeutics ($275M) raised $1.18B in total.
By stage, Late-Stage's 69 rounds took $19.84B, about double August's $9.81B. Series B drew $3.32B across 54 rounds, Series A $2.97B across 119 rounds, and Early-Stage $1.75B across 512 rounds, the most crowded stage by round count but only 6.3% of capital.
Geographically, California led with $9.58B, or 34% of the total. Colorado ($4.32B, almost entirely Crusoe) and Texas ($4.17B, led by The Boring Company and Island) ranked second and third. New York raised $3.14B across 59 rounds, or 11.2% of US capital, up from 4.8% in August and 49% higher than September 2025 on a capital basis.
AlleyWatch notes that Q3 closed at about $65.43B, with July at $19.44B and August at $18.1B. Methodology excludes undisclosed rounds, corporate rounds, private equity and debt. Early-Stage covers Pre-Seed through Accelerator and Incubator rounds, with Series A and B reported individually and Late-Stage covering Series C and later.
Four rounds of $1B or more drove a significant share of activity. Crusoe's $3.9B Series F, co-led by Atreides, Mubadala Capital and Valor Equity Partners, topped the month. The Boring Company raised $3.0B in a Series D led by Valor Equity Partners, Sequoia Capital and Andreessen Horowitz, while Cognition raised $2.0B in a Series E and Stoke Space raised $1.0B in a Series E. Those four rounds totaled $9.90B.
By sector, AI infrastructure was the deepest pool. Crusoe, Positron ($875M), Gimlet Labs ($300M), Celero ($275M), GMI Cloud ($223M) and Cornelis Networks ($205M) together raised $5.78B across compute, chips and networking. Software-side AI rounds, including Cognition, Harvey ($550M) and Snorkel AI ($350M), added $2.90B. Space and defense companies Stoke Space, Mach Industries ($600M) and Impulse Space ($308M) raised $1.91B. Health companies led by Enveda ($311M) and Encoded Therapeutics ($275M) raised $1.18B in total.
By stage, Late-Stage's 69 rounds took $19.84B, about double August's $9.81B. Series B drew $3.32B across 54 rounds, Series A $2.97B across 119 rounds, and Early-Stage $1.75B across 512 rounds, the most crowded stage by round count but only 6.3% of capital.
Geographically, California led with $9.58B, or 34% of the total. Colorado ($4.32B, almost entirely Crusoe) and Texas ($4.17B, led by The Boring Company and Island) ranked second and third. New York raised $3.14B across 59 rounds, or 11.2% of US capital, up from 4.8% in August and 49% higher than September 2025 on a capital basis.
AlleyWatch notes that Q3 closed at about $65.43B, with July at $19.44B and August at $18.1B. Methodology excludes undisclosed rounds, corporate rounds, private equity and debt. Early-Stage covers Pre-Seed through Accelerator and Incubator rounds, with Series A and B reported individually and Late-Stage covering Series C and later.
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