Other than turning into a family identify with the breakout success of ChatGPT in 2022, OpenAI CEO Sam Altman has lengthy been one in all Silicon Valley’s most influential startup traders. Lengthy earlier than generative A.I. captured world consideration, Altman constructed a popularity as a prolific angel investor whose bets helped form the trendy tech panorama, from early stakes in Stripe, Reddit and Instacart to later, high-conviction investments in nuclear power and longevity science.
Altman’s monitor document as an early-stage investor was formed throughout his time at Y Combinator, the place he served as president from 2014 to 2019. In that position, he helped oversee investments in a whole bunch of startups, a number of of which went on to turn out to be main know-how firms. After leaving YC, Altman continued to take a position personally in each alumni firms and new ventures.
Through the years, Altman has invested in additional than 400 firms by a mixture of private angel checks, his personal funds like Hydrazine Capital and Apollo Initiatives, and partnerships with bigger enterprise corporations.
Altman’s 2025 funding exercise has centered on startups in A.I.-driven safety, biotechnology and nuclear fusion, in line with Crunchbase knowledge. These bets replicate not only a want to diversify throughout cutting-edge industries, but additionally to champion “moonshot” ventures tackling a few of at this time’s most complicated challenges, from intelligence augmentation and clear power to breakthroughs in human well being.
Listed here are the startups that Altman invested on this 12 months:
Helion Power
- Product: fusion energy
- Funding channel: private/angel investing
- Funding: $425 million Sequence F in January
- Valuation: $5.4 billion
Helion Power is a nuclear fusion firm working to commercialize fusion energy as a zero-carbon power supply. The corporate is constructing its first fusion energy plant in Chelan County, Wash. scheduled to return on-line in 2028. As knowledge facilities and superior A.I. techniques drive a surge in electrical energy demand, curiosity in scalable, emissions-free energy has grown throughout the tech trade. Helion is positioning itself to fulfill that demand with a patented pulsed, non-ignition fusion strategy designed to generate electrical energy instantly, with out counting on conventional steam generators. Altman has been one of many firm’s most outstanding backers for a number of years, calling Helion in 2021 “by far probably the most promising strategy to fusion I’ve ever seen.” His newest funding got here as a part of Helion’s $425 million Sequence F spherical in January.
MirrorTab
- Product: net safety know-how
- Funding channel: Altman Capital
- Funding: $8.5 million seed spherical in February
- Valuation: not disclosed
MirrorTab develops browser-based safety instruments that defend customer-facing net functions from threats together with malware, automated fraud, refined bots and so-called agentic A.I. abuse. MirrorTab makes use of pixel-streaming know-how to stop untrusted browsers, extensions and scripts from accessing delicate knowledge or code, with out requiring customers to put in further software program. “Most distributors are centered on enabling A.I.—far fewer are working to limit it,” CEO and founder Brian Silverstein stated at a latest convention. “Efficient A.I. safety requires realizing when to leverage A.I. and when to dam it totally.”
Campus
- Product: On-line instructional companies
- Funding channel: private/angel investing
- Funding: $46 million Sequence B in March
- Valuation: $100 million
Campus is an internet, two-year school providing lower-cost accredited levels taught by professors from establishments together with Stanford, Princeton, and Howard College. College students attend reside on-line courses and complement coursework with A.I.-generated instructional instruments developed by Sizzle A.I. The college presently affords affiliate levels in enterprise administration and knowledge know-how, with an non-compulsory focus in utilized A.I. centered on enterprise use circumstances. Altman backed Campus by its $46 million Sequence B spherical, alongside traders similar to Figma CEO Dylan Subject, Palantir co-founder Joe Lonsdale and Shaquille O’Neal. Altman additionally helps fund the corporate’s Shaq Students Program, which offers monetary help to enrolled college students.
ConductorAI
- Product: automation software program
- Funding channel: Altman Capital
- Funding: $15 million Sequence A in April
- Valuation: not disclosed
Based by former Palantir workers, ConductorAI focuses on automating complicated authorities approval and compliance workflows. The corporate’s software program, which has been contracted by the U.S. Air Drive, House Drive and the Workplace of the Secretary of Protection, makes use of A.I. to overview giant volumes of coverage and regulatory paperwork. In accordance with Enterprise Insider, ConductorAI has primarily been used to automate safety classification, with further functions in export licensing, Worldwide Visitors in Arms Rules compliance and doc overview.
Exowatt
- Product: renewable power
- Funding Channel: angel investing
- Funding: $70 million Sequence A in April and $50 million in November
- Present valuation: $140 million
Exowatt builds modular energy techniques designed to ship large-scale, on-demand power. Its know-how makes use of Fresnel lenses to pay attention daylight into thermal power, which is saved in ceramic bricks that perform as batteries for the system’s engine and energy generator. Whereas the underlying strategy just isn’t new, Exowatt is betting that recent capital—from Altman, enterprise agency Andreessen Horowitz and traders together with Leonardo DiCaprio—will enable it to fabricate and deploy techniques domestically at velocity. The objective is to serve knowledge facilities dealing with surging demand for round the clock energy that’s low-cost, dependable and low-carbon.
Coco Robotics
- Product: supply robots
- Funding channel: private/angel investing
- Funding: $80 million Sequence B in June
- Valuation: $300 million
Altman was a lead investor in Coco Robotics’ $80 million Sequence B spherical in June 2025. The Santa Monica–based mostly startup builds small supply robots used for last-mile logistics by platforms together with DoorDash and Uber Eats. Coco’s robots depend on GPS, LiDAR cameras and A.I. techniques powered partly by OpenAI fashions to navigate dense city environments and make real-time routing selections. Since launching in 2020, the corporate has deployed robots in cities together with Los Angeles, Austin, Miami and Helsinki. Growth has drawn scrutiny, nevertheless: in Chicago, greater than 800 residents had signed a petition by late November calling for a pause to Coco’s pilot program, citing security and accessibility issues.
Arcadia Medication
- Product: bioengineered psychoactive medicines
- Funding channel: private/angel investing
- Funding: $9.25 million seed spherical in October
- Valuation: not disclosed
Arcadia Medication develops engineered entactogens—psychoactive compounds designed for therapeutic use—to deal with situations similar to main depressive dysfunction, generalized nervousness dysfunction and substance use dysfunction. The corporate creates modified variations of medication together with MDMA, psilocybin and ketamine, aiming to reinforce their therapeutic advantages whereas decreasing security dangers to fulfill medical and regulatory requirements.
In October, the U.S. Meals and Drug Administration accepted human trials for Arcadia’s redesigned MDMA compound, which the corporate says is non-neurotoxic and permits for versatile dosing. Altman participated within the firm’s $9.25 million seed spherical and has publicly described its work as “an vital step towards a doubtlessly transformative psychiatric remedy,” lending early credibility as Arcadia prepares for extra superior scientific trials.
Crimson Queen Bio
- Product: biosecurity
- Funding channel: OpenAI
- Funding: $15 million seed spherical in November
- Valuation: $20 million–$25 million
Crimson Queen Bio is a biosecurity startup that emerged from Helix Nano, an mRNA therapeutics firm that applies A.I. to drug growth and organic threat evaluation. Named after the “Crimson Queen speculation,” which posits that species should constantly adapt to outlive towards evolving threats, the corporate goals to construct safeguards for superior A.I. techniques on the identical tempo as their capabilities enhance. Whereas Altman didn’t make investments instantly in Crimson Queen Bio, his prior backing of Helix Nano resulted in an fairness stake when OpenAI led Crimson Queen Bio’s November seed spherical, positioning the startup as a part of OpenAI’s broader effort to handle organic dangers tied to highly effective A.I. fashions.
