TEMPO.CO, Jakarta - Widely recognized as a prolific angel investor, OpenAI’s CEO Sam Altman has long stood as a formidable pillar in the global startup ecosystem. Well before the rise of ChatGPT catapulted him into the public spotlight, Sam Altman’s investments had already made waves across an array of industries.
His strategic foresight was sharpened during his pivotal years at Y Combinator, where, between 2011 and 2019, he played an instrumental role in shaping Silicon Valley’s next generation of innovators.
Even after stepping down from his leadership post at Y Combinator, Altman’s commitment to nurturing visionary founders remained steadfast. The celebrated figure in artificial intelligence has continued to channel his capital and conviction into promising enterprises, amassing a portfolio that now spans nearly 400 companies.
To grasp the magnitude of his footprint in the startup landscape, here are some of Sam Altman’s investments within the $100 million milestones, highlighted by sources such as Observer, CB Insights, and Tracxn.
Sam Altman’s Investments in $100 Million Brackets
1. Helion Energy: nuclear fusion energy
Among Sam Altman’s investments, none stands more emblematic of his audacious vision than his deep commitment to Helion Energy, a pioneering firm at the forefront of nuclear fusion innovation. Nuclear fusion, the process of generating immense power by fusing atomic nuclei, has long been hailed as the holy grail of clean energy yet remains commercially elusive.
In 2021, Altman placed an extraordinary vote of confidence in the company, investing $375 million during its Series E round, marking his largest personal investment to date and valuing Helion at $2.5 billion. His conviction only deepened as he joined a consortium of backers in January 2024, contributing an additional $425 million in Series F funding, doubling the company’s valuation to $5.4 billion.
2. Wave Mobile Money: fintech
Across Altman’s portfolios, Wave Mobile Money exemplifies his unwavering faith in technology as a catalyst for global financial empowerment. Founded by Drew Durbin and Lincoln Quirk, the visionary duo behind the remittance platform Sendwave, Wave seeks to revolutionize access to banking and financial services across Africa through mobile-first solutions for transfers and microloans.
In September 2021, the company made history by securing a monumental $200 million Series A round, the largest ever recorded in the region at the time, catapulting its valuation to $1.7 billion. The funding round attracted a constellation of heavyweight backers, including Sam Altman, Founders Fund, Sequoia Heritage, Ribbit Capital, and Stripe.
3. Hermeus: supersonic aviation
Hermeus is pushing the boundaries of aviation with its quest to build the world’s fastest supersonic jets. In March 2022, the company secured a $100 million Series B funding round led by Sam Altman, with additional backing from Founders Fund, In-Q-Tel, Khosla Ventures, and Canaan Partners.
The fresh capital is fueling the completion of Quarterhorse, Hermeus’ first prototype, and advancing work on Darkhorse, an uncrewed aircraft engineered for sustained hypersonic flight. The experience gained from these breakthroughs will ultimately shape the development of Halcyon, a commercial passenger aircraft envisioned to revolutionize air travel by making high-speed, long-distance flights a practical reality.
4. Rescale: cloud software
Rescale has emerged as a transformative force in the realm of cloud computing, providing engineers and scientists across industries such as aerospace, automotive, and energy with the tools to design, simulate, and optimize complex systems through advanced computational power.
Since its inception, the company has attracted an elite roster of backers, including Sam Altman, Jeff Bezos, Paul Graham, and Peter Thiel, who share its vision of accelerating innovation through scalable digital infrastructure.
Altman, in particular, has shown unyielding confidence in the company’s trajectory, investing repeatedly since its seed round in 2012 and participating in subsequent funding stages, including a $115 million Series D round in April 2024.
5. Oklo: nuclear energy
Founded in 2013 by Caroline Cochran and Jacob DeWitte, the company was among the earliest ventures supported by Sam Altman during his tenure at Y Combinator, where he invested $120,000 in its 2014 seed round.
Oklo’s ambition and technological promise have since propelled its valuation to $300 million following a Series B in 2021, culminating in its public debut in May 2024 through a reverse merger with AltC Acquisition Corp, a SPAC also backed by Altman.
Through his far-reaching portfolio, Sam Altman’s investments reveal a forward-looking vision for humanity’s technological evolution. As industries continue to evolve under the influence of such visionary leadership, Altman’s footprint in the startup world serves as both a guidepost and an inspiration for future entrepreneurs.
To explore how other trailblazers are reshaping the global business landscape, read our feature on today’s most influential business leaders.
Editor’s Choice: Sam Altman Says OpenAI Interested in Acquiring Chrome Browser
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