The 10 largest startup rounds announced between Saturday, Sep 26 and Saturday, Oct 3, 2026 added up to $3.39B. Every round below is checked against a published announcement or report, with the lead investor and a link to the source.
- $3.39B
- Raised by the top 10
- $1B
- Largest round (Instinct)
- Sep 26 – Oct 3, 2026
- Announcement window
Key takeaways
- Instinct ($1B) and FieldAI ($700M) account for half of the top-10 total, and both were valued at $10B.
- 8 of the 10 companies build AI products or AI infrastructure, from personal agents and robot brains to GPU clouds and drug discovery.
- Biossil became a new unicorn at a $1B valuation in a round led by the OpenAI Startup Fund, and Supabase paired its $150M raise with a deal to acquire Turso.
The 10 biggest startup rounds, Sep 26 – Oct 3, 2026
Ranked by round size. Company names link to their websites; each round links to the announcement or report it was verified against.
| # | Company | Amount & round | Announced | Lead investor | Source |
|---|---|---|---|---|---|
| 1 |  | $1B Series C $10B valuation | Sequoia, Benchmark, Coatue | Source for the Instinct round | |
| 2 |  FieldAI General-purpose AI brain for field robots Reported by Business Insider from a term sheet; some outlets say the round has not formally closed. Robotics | $700M Growth round (reported) $10B valuation | Undisclosed | Source for the FieldAI round | |
| 3 |  | $350M Series F $4B valuation | a16z, Bessemer | Source for the EliseAI round | |
| 4 |  | $255.5M Series B $2.5B+ valuation | a16z, Accel | Source for the Armadin round | |
| 5 |  GMI Cloud GPU cloud and inference for AI teams Also took a separate $445M credit facility, not counted in the amount. AI infrastructure | $223M Series B | ARCHIV | Source for the GMI Cloud round | |
| 6 |  | $220M Growth round $6.2B valuation | Backed byValor, Atreides, Khosla +3 Valor Equity Partners, Atreides, 776, Point72, Khosla Ventures and General Catalyst; no single lead named. | Source for the General Intuition round | |
| 7 |  | $180M Series C | Velumani Family Office | Source for the Simple Energy round | |
| 8 |  | $155M Growth round | Backed byExisting investors (incl. Schwab, BlackRock, Citadel Securities) | Source for the TXSE Group round | |
| 9 |  | $153M Growth round $1B valuation | OpenAI Startup Fund | Source for the Biossil round | |
| 10 |  Supabase Postgres backend for developers and AI agents Also announced it is acquiring Turso. Developer tools | $150M Growth round | GIC | Source for the Supabase round |
Methodology
- Window: rounds announced from Saturday, Sep 26, 2026 to Saturday, Oct 3, 2026.
- Ranking: by round size. Ties go to the company with higher estimated revenue where the data separates them.
- Scope: startups only. Public companies, debt facilities, project finance, private equity buyouts, acquisitions and strategic stakes are excluded.
- Verification: each round is checked against a published announcement or report, linked in the Source column.
- Labels: "Growth round" means the company did not disclose a series letter. "Backed by" means no single lead investor was named. "Reported" means the round is based on press reports and may not have formally closed.
Why this matters for B2B sellers
A fresh round usually turns into new hiring and new tooling budget within about 90 days, as founders put the money to work. The weeks right after an announcement are the best time to reach the people who will own that budget, before vendor shortlists are set. SyncGTM tracks funding signals like these, and its company funding template pulls the latest round, amount, date and investors for any account list.