Sam Altman
Partner @ Y Combinator
San Francisco, United States
Sam Altman is a seed investor at Y Combinator in San Francisco focused on Software and Artificial Intelligence. Sam Altman is the Co-Founder and CEO of OpenAI. Sam previously served as Board Chair at Helion Energy.
- Total investments:
- 199
- Last investment:
- Lead investor:
- 24%
Last updated:
For AI agents: llms.txt
Industries Sam Altman invests in
Stages Sam Altman invests in
Countries Sam Altman invests in
Round sizes
Contacts
| Type | Contact | Validation |
|---|---|---|
| Work email | ||
| Personal email | ||
| Work phone | ||
| Personal phone | ||
| Socials |
Round size
- Seed
- $1.2M–$9.3M
- Series A
- $10M–$50M
- Series B
- $17M–$100M
Investment Focus
Industry
- Software 38 (19%)
- Artificial Intelligence 27 (14%)
- Information Technology 18 (9%)
- Biotechnology 16 (8%)
- E-Commerce 15 (8%)
Stage
- Seed 81 (41%)
- Series A 38 (19%)
- Series B 23 (12%)
- Pre-Seed 11 (6%)
- Series C 10 (5%)
Country
- United States 125 (63%)
- Canada 2 (1%)
- Ghana 1 (1%)
- Libya 1 (1%)
- Israel 1 (1%)
Investments
| Company | Description | Round | Links |
|---|---|---|---|
| Modular Full-Stack Renewable Energy Solutions for Commercial and Industrial Applications | $50M / Series A / Nov 13, 2025 | ||
| Red Queen Bio works with frontier labs to map AI-enabled biothreats and pre-build medical countermeasures against them. | $15M / Seed / Nov 13, 2025 | ||
| Preventive mission is to determine whether the newest generation of gene editing technologies can be used safely and responsibly to correct devastating genetic conditions for future children. | $30M / Venture - Series Unknown / Oct 30, 2025 | ||
| Arcadia Medicine is a biotechnology company that creates psychedelic medicine to treat mental health issues. | $9.3M / Seed / Oct 06, 2025 | ||
| Coco is a last-mile delivery service that deploys human-operated sidewalk robots to transport goods from merchants to their customers. Its robot fleet serves thousands of customers per week in Santa Monica, Los Angeles, Austin, and Houston, paving the way for a more optimistic future of delivery that benefits local communities.Launched inFebruary 2020, the company has partnered with national restaurant brands like SBE (Umami Burger) and is actively scaling across many locations. It serves a wide range of family-operated restaurants like Bangkok West Thai in Santa Monica and San Pedro Brewing Company in Los Angeles. | $80M / Series B / Jun 11, 2025 | ||
| Modular Full-Stack Renewable Energy Solutions for Commercial and Industrial Applications | $35M / Series A / Apr 22, 2025 | ||
| Rescale is a cloud simulation platform that enables research scientists and engineers to build, compute, analyze, and scale simulations.The high-performance computing cloud platform delivers intelligent computing for digital R&D and enables more than 300 customers from startups to Fortune 50 enterprises to accelerate design cycles and time tomarket. Rescale gives research scientists and engineers the ability to run their simulation and artificial intelligence workloads on the cloud provider of their choice, using specialized hardware architectures and software templates optimized for their use cases, without any set-up or maintenance. Investors such as Initialized Capital, Keen Venture Partners, SineWave Ventures, Data Collective, ITV Ventures, Jump Capital, and M12 (formerly Microsoft Ventures), as well as Mitsubishi UFJ Capital, Quiet Capital, Streamlined Ventures, Translink Capital, Two Roads Group, Y Combinator, Hitachi Ventures, Nautilus Venture Partners, NVIDIA, Republic Labs, and Samsung Catalyst Fund backs Rescale.In 2011, Joris Poort and Adam McKenzie headquartered the company in San Francisco, California. | $115M / Series D / Apr 07, 2025 | ||
| Campuswire is a real-time messaging app for college classes that streamlines class discussions, Q&A, and announcements. The company on a mission to optimize the world’s teaching and learning. They are assembling a world-class team of engineers, designers, pedagogists, and more to solve problems in teaching and learning. | $46M / Series B / Mar 20, 2025 | ||
| Operator of a patented plasma accelerator technology designed to address the growing need for clean energy. The company's technology specializes in designing fusion generators based on magneto-inertial fusion with a fifty-megawatt module and energy regeneration, thereby enabling customers to use low-cost, clean, and safe energy. | $425M / Series F / Jan 28, 2025 | ||
| Retro Biosciences focuses on cellular reprogramming, autophagy, and plasma-inspired therapeutics. The company is engaged in cellular reprogramming, autophagy, and developing therapeutics inspired by plasma to combat aging. Retro Biosciences aims to extend healthy human lifespan by 10 years through innovative biotechnology focused on aging. | $1B / Series A / Jan 24, 2025 | ||
| See all 199 investments → | |||
Co-Investors
About Y Combinator
Y Combinator invests a standard amount of capital in exchange for equity and through uncapped safe agreements. Participants engage in a three-month intensive cycle that focuses on product development and preparations for fundraising. The firm offers access to a private networking platform for knowledge sharing and hosts events featuring speakers from various sectors. This program culminates in a presentation event where founders showcase their businesses to a curated group of investors.
Y Combinator Contacts
| Name | Phone | Socials | |
|---|---|---|---|
Boris Jabes
Visiting Partner
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Luther Lowe
Head of Public Policy
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Max Kolysh
Visiting Partner
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Brad Flora
Group Partner
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Calvin French-Owen
Visiting Group Partner
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FAQ
What does Sam Altman invest in?
Sam Altman invests primarily in Software, Artificial Intelligence and Information Technology startups, most often at Seed and Series A stage. Most of the 199 investments tracked by Shizune back companies in United States. The Investment Focus section breaks down every industry, stage and country in the portfolio.
What round sizes does Sam Altman invest in?
Sam Altman typically joins rounds of $1.2M–$9.3M at Seed, $10M–$50M at Series A and $17M–$100M at Series B. These are whole funding-round sizes, not Sam Altman's own check, which is rarely disclosed: the 10th–90th percentile of the confirmed public funding rounds Sam Altman took part in.
How do I contact Sam Altman?
Public channels for Sam Altman include LinkedIn, X (Twitter) and the website linked on this profile. For a verified work email and phone number, create a free Shizune account — contact data is searched across 20+ sources and validated before delivery, so your outreach lands in the right inbox.
When did Sam Altman last invest?
The most recent investment recorded for Sam Altman closed in Nov 2025. Shizune tracks 199 investments in total for this profile, including round sizes, stages and portfolio companies, all sourced from confirmed public funding rounds and refreshed monthly.
Is Shizune's investor data accurate?
Yes — every stat on this profile is calculated from confirmed public funding rounds monitored across hundreds of sources since 2020. This profile was last refreshed in Oct 2026 and is updated monthly. Spotted something off? Use the “Suggest an edit” link near the top of the page.
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