Companies Sam Altman Invested in: Reddit, Neuralink, More

Helion Energy

In July 2014, Y Combinator invested $1 million in Helion Energy’s Series A round, according to PitchBook. Altman led the company’s Series E round in November 2021, investing $375 million into the fusion energy company. Helion Energy raised $500 million in that round, according to PitchBook.

Helion Energy converts a form of hydrogen called deuterium into helium-3, which it says is “the ideal fuel for fusion electricity.”

Altman said in an interview that Helion is “more than an investment to me,” and that apart from spending time on OpenAI, he’s spent “a lot of time” on Helion because he’s “super excited about what’s going to happen there.”

Helion Energy was founded by David Kirtley, Chris Pihl, and George Votroubek.