Monthly roundup · Cybersecurity · September 2026

Cybersecurity startup funding, September 2026: Island's $400M Series F leads 24 rounds

By Millionrounds ResearchPublished 1 October 2026Updated 16 October 2026

We read 24 equity rounds in Cybersecurity announced in September 2026, raising $1.5B between them: 7% of all the rounds we read that month and 4% of the money. The largest was Island's $400M Series F, led by Evolution Equity Partners. The median seed round was $6.3M, against $10M over the last twelve months in Cybersecurity; at Series A it was $21M.

Equity rounds24in Cybersecurity, 23 with an amount
Raised$1.5Bacross those rounds
Lead named92%of rounds say who led
Share of the month7%of rounds; 4% of the money

The biggest rounds

  1. 1IslandSeries F · United States · led by Evolution Equity Partners$400M
  2. 2CCyeraGrowth · United States · led by Goldman Sachs Alternatives$400M
  3. 3ExeinGrowth · Italy · led by Headline$270M
  4. 4HHiddenLayerSeries B · United States · led by Delta-v Capital$100M
  5. 5MMINDSeries B · United States · led by Crosspoint Capital Partners$72M
  6. 6BaselayerSeries A · United States · led by M13$35M
  7. 7CymphonySeries A · United States · led by Sequoia Capital, SMBC Fin Atlas Beyond Fund$30M
  8. 8HHuskeysSeries A · United States · led by Blackstone Innovations Investments$27M
  9. 9QNu LabsSeries A · India · led by Speciale Invest, National Quantum Mission$21M
  10. 10HackuitySeries B · France · led by ForgePoint Capital$19M

Day by day

Equity rounds in Cybersecurity announced each day of September. The busiest day was 9 September, with 4.

1 September30 September

By stage, against the year

Each stage's median this month beside its twelve-month median: the sector's own where we hold enough rounds for a benchmark, otherwise the one across all sectors.

Pre-seed4$2.1Mthis month$2.0M12 months, all sectors
Seed5$6.3Mthis month$10M12 months here
Series A8$21Mthis month$25M12 months here
Series B3$72Mthis month$58M12 months here
Growth2$335Mthis month$113M12 months, all sectors

Where

United States had the most Cybersecurity rounds this month.

Against the month

  • Rounds, Cybersecurity24
  • Rounds, all sectors357
  • Raised, Cybersecurity$1.5B
  • Raised, all sectors$39B

The whole of September 2026

Other sectors in September

195 roundsAI→51 roundsFintech→39 roundsHealthcare→30 roundsBig Data & Analytics→27 roundsBiotech→25 roundsRobotics→23 roundsHardware & Electronics→22 roundsEnterprise Software→21 roundsSoftware→21 roundsEnergy→21 roundsConstruction→20 roundsHealthtech→20 roundsSaaS→19 roundsLogistics→17 roundsManufacturing→16 roundsCleantech→14 roundsAerospace & Space→14 roundsDefence Tech→13 roundsTelecoms→13 roundsSemiconductors→13 roundsClimate Tech→11 roundsAutomotive & EVs→10 roundsCloud→