Y Combinator

Focus: Legal & compliance, AI, Defence & space, Fintech, Developer tools, Healthtech & bio, Cybersecurity

Y Combinator took part in 14 of the startup funding rounds we tracked in 2026, leading or co-leading 1 worth $9.5m. By money raised, its biggest sectors were AI and Defence & space. The largest was River AI's $1.1bn Series A round. The most recent was Infisical's Series B round in October 2026.

Deployed as lead$9.5m

Rounds led1

Rounds joined14

Largest round$1.1bn

Rounds led (1)

BioStackSeed · Healthtech & bio · San Francisco · 22 Oct$9.5m

Also invested (13)

InfisicalSeries B · Cybersecurity · San Francisco · 27 Oct$40m Vera HealthSeries A · Healthtech & bio · San Francisco · 27 Oct$28.5m Kivo HealthSeries A · Healthtech & bio · San Francisco · 23 Oct$10m TractianSeries D+ · AI · Atlanta · 22 Oct$130m BlacksmithSeries C · Developer tools · San Francisco · 21 Oct$66m Nous ResearchSeries B · AI · United States · 7 Oct$90m NumeralSeries C · Fintech · San Francisco · 23 Sep$100m ConfidoSeries B · AI · New York · 22 Sep$55m ComplirSeed · Legal & compliance · Copenhagen · 16 Sep$11m Stoke SpaceSeries D+ · Defence & space · Kent · 8 Sep$1bn River AISeries A · AI · Palo Alto · 11 Aug$1.1bn HappyRobotSeries C · AI · San Francisco · 4 Aug$150m LegoraSeries D+ · Legal & compliance · Stockholm · 10 Mar$550m

Y Combinator

Rounds led (1)

Also invested (13)

By sector

By stage

Co-investors