Amazon-backed X-energy files for IPO to raise up to $800 million

Nuclear startup X-energy began its investor roadshow on Wednesday as it works toward an Initial Public Offering (IPO). According to documents filed with the U.S. Securities and Exchange Commission (SEC), the company set its target price between $16 and $19 per share. If the company lists at the high end of this range, it could net about $814 million. This public listing attempt marks a recovery from a failed effort in 2023, when X-energy canceled a planned reverse merger with a Special Purpose Acquisition Company (SPAC).

The company’s financial breakdown includes:

• IPO target: Up to $800M in total raise.
• Series C-1 funding: A $500 million round led by Amazon.
• Total investment: About $1.8 billion raised to date, according to data provider PitchBook.

Amazon is both a lead investor in the Series C-1 round and a future customer for nuclear power, having pledged to buy as much as 5 gigawatts of nuclear power from X-energy by 2039. X-energy’s reactor design is a high-temperature, gas-cooled reactor that uses TRISO—a fuel design expected to be safer than previous arrangements, where uranium is encased in ceramic and carbon spheres and cooled by helium gas. The gas then transfers heat to a steam turbine loop to generate electricity, though this fuel design is not widely used today.

However, the SEC filing reveals that X-energy is already embroiled in a patent dispute with another company that recently went bankrupt. Ultra Safe Nuclear Corporation (USNC) went bankrupt in 2024, and its assets were purchased to form Standard Nuclear. X-energy alleges that USNC infringed on its fuel fabrication patents, and the startup notes that the matter has not been resolved to its satisfaction during the bankruptcy proceedings.

This commercial push comes amid broader geopolitical and regulatory pressures. Outside of China, the development of new nuclear reactors has largely stalled due to delays and cost overruns. Small modular reactor startups in the U.S. are currently racing to meet a July 4 deadline set by the Trump administration. While startups race to meet this deadline, they are still working to achieve criticality—the moment when fission reactions become self-sustaining. However, the road to profitable power plants is long, as mass manufacturing typically takes around a decade to pay dividends. X-energy expects to be able to bring costs down by 30% relative to the first-of-a-kind reactor once its production techniques mature into the “Nth-of-a-kind” stage.

Why it matters

X-energy’s IPO filing marks a significant step for the nuclear startup, which is backed by Amazon and is navigating a patent dispute while attempting to scale its high-temperature, gas-cooled reactor technology.