Y Combinator
Accelerator · Founded 2005 · San Francisco, CA
Portfolio
4000+
Y Combinator is the world's most influential startup accelerator that launched Airbnb, Stripe, and thousands more.
Notable Investments
Recent Portfolio Activity
xAI
AI/ML · Series B
$6.0B
Dec 2024
Mistral AI
AI/ML · Series B
$640M
Jun 2024
ElevenLabs
AI/ML · Series C
$180M
Jan 2025
Joby Aviation
Defense Tech · Strategic
$500M
Oct 2024
Relativity Space
Defense Tech · Series E
$650M
Jun 2023
Commonwealth Fusion Systems
Climate/Energy · Series B
$1.8B
Dec 2021
Form Energy
Climate/Energy · Series E
$450M
Apr 2023
Ramp
Fintech · Series D
$300M
Aug 2023
Nuvation Bio
Health · Series B
$275M
Apr 2021
GRAIL
Health · Series D
$390M
May 2020
Stability AI
AI/ML · Series A
$101M
Oct 2022
Deel
Fintech · Series D
$425M
May 2022
Details
Type
Accelerator
Founded
2005
HQ
San Francisco, CA
Portfolio Size
4000+ companies
AUM
Undisclosed