Helion Raises $465 Million to Build Orion Power Plant for Microsoft, Valued at $15.5 Billion

Helion, the fusion startup backed by Sam Altman, announced on Thursday that it had raised $465 million in a new funding round valuing the company at $15.5 billion.

The cash infusion arrives as Helion races to complete Orion, its first power plant, with an aggressive timeline to deploy fusion power to the grid as early as 2028 if it can deliver on the terms of its deal with Microsoft.

Crypto Briefing

Helion said it is now valued at $15.5 billion and that it has raised $1.5 billion overall, after previously obtaining $425 million in January 2025.

GeekWire reported the Everett, Wash.-based company broke ground on the 50-megawatt plant, dubbed Orion, last July in Malaga, Wash.

Helion’s Series G round was led by Thrive Capital, with participation from new investors including Alta Park Capital, Anti Fund, BoxGroup, Lux Capital, Peak XV Partners, and Bill Ford.

Helion is operating under the sector’s most ambitious timeline, signing a deal with Microsoft to supply energy to a Central Washington data center by 2028.

GeekWire said Helion’s critics raise concerns about the startup’s secrecy and limited scientific publications, making it difficult for independent researchers to evaluate its approach.

IndexBox

In a statement, Helion co-founder and CEO David Kirtley said his company is best positioned to generate electricity from fusion this decade.

TechCrunch described Helion’s method as using magnets to compress the superheated plasma required for fusion conditions, while other startups use lasers to compress fusion fuel until it reacts.

TechCrunch also reported that David Kirtley argued, “We don’t want to theorize about fusion,” and “We just want to go build it.”

Helion is building toward Orion while running tests in Everett on Polaris, its 60-foot-long, seventh-generation fusion device, and it recently revealed it is building another machine called Tiny Merge.

“Sustainability:News about the rapidly growing climate tech sector and other areas of innovation to protect our planet”

GeekWire

GeekWire quoted Michael Hua, Helion’s senior director of radiation safety and nuclear science, saying, “With this agile testbed, we will be able to test new ideas with much less energy and far fewer resource requirements.”

The funding also places Helion in a broader competitive field, with Commonwealth Fusion Systems “vying to be the first to harness fusion, targeting the early 2030s,” according to GeekWire.

TechCrunch reported that Helion intends to harvest electricity straight from the magnets themselves, drawing off the force as electricity when fusion occurs in the plasma inside the reactor.

TechCrunch said some fusion experts are skeptical it could work because Helion doesn’t frequently publish in peer-reviewed journals, so physicists haven’t been able to examine the theoretical underpinnings.