Investing Profile

Sam Altman

AngelInvestorFounder
Co-founder and CEO of OpenAI
blog.samaltman.comSan Francisco, California
Photo of Sam Altman, Angel

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Y Combinator Network
38 CONNECTIONS
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Angel
$100K - $5.0M
$1.5M
171
CompanyStageDateRound SizeTotal Raised
Red Queen Bio
SeedNov 2025$15M
$15M
Exowatt
Series ANov 2025$50M
Series AApr 2025$35M
SeedApr 2024$20M
$110M
Co-investors: Viviana Faga (Felicis Ventures), Aydin Senkut (Felicis Ventures), Katherine Boyle (Andreessen Horowitz), Andre De Baubigny (Modern Venture Partners), Jack Abraham (Atomic), Leonardo DiCaprio
Arcadia Medicine
SeedOct 2025$9M
$9M
Co-investors: Fred Ehrsam (Paradigm), Dylan Field
Coco
Series BJun 2025$80M
Series AAug 2021$36M
$120M
Co-investors: Jeff Kearl (Pelion Venture Partners), Paige Craig (Outlander Labs), Max Altman (Saga), Kevin Mahaffey (SNR), Dick Boyce (TPG), Sam Nazarian, Tom Steyer, Abe Burns
Rescale
Series DApr 2025$120M
Series CNov 2021$55M
Series BJul 2018$32M
Series UnknownJul 2015$6M
SeedJan 2012
$270M
Co-investors: Nagraj Kashyap (Softbank Group), Chris Dixon (Andreessen Horowitz), Ronald Conway Sr. (SV Angel), Ullas Naik (Streamlined Ventures), Peter Thiel (Founders Fund), Lorenzo Thione (Gaingels), Ron Conway (SV Angel), Wei Guo (UpHonest Capital), Garry Tan (Y Combinator), Wolfgang Seibold (Hitachi Ventures), Dr. E. Bora Uygun (Bora&Sons), Raj Sandhu (Great Oaks Venture Capital), Peter Bordes (Trajectory Ventures), Shankar Chandran (Walden Catalyst Ventures), Jeff Bezos, Richard Branson
Campus
Series BMar 2025$46M
Series AMay 2023$29M
$100M
Co-investors: Joe Lonsdale (8VC), Trae Stephens (Founders Fund), Rob Hayes (First Round Capital), Thomson Nguyen (Saga), Max Altman (Saga), Lachy Groom (LGF), Elizabeth Weil (Scribble Ventures), Jason Citron, Emil Michael, Dylan Field, Ron Pragides, Akshay Kothari
Helion Energy
Series FJan 2025$430M
Series ENov 2021$500M
Series DSep 2020$40M
SeedAug 2014$1M
$970M
Co-investors: Ravi Mhatre (Lightspeed Venture Partners), Dustin Moskovitz
Boom Supersonic
Series ADec 2024$100M
Series BApr 2019$100M
Series AMar 2017$33M
SeedMar 2016$6M
$330M
Co-investors: Reid Hoffman (Greylock), Avichal Garg (Electric Capital), Josh Buckley (Buckley Ventures), Wei Guo (UpHonest Capital), Max Altman (Saga), Luigi Bajetti (LombardStreet Ventures), Zia Huque (Prime Movers Lab), Eric Lefkofsky (Lightbank), Harshul Sanghi (American Express Ventures), Michael Marks (Celesta), Alexander Piskunov (KAAN Ventures), Jude Gomila (Jude Gomila Rolling Fund), Louis Beryl, Matt Bellamy, Alexander Gerko, Michael Moritz, Mattia Astori
President Y Combinator2016 - 2019