Amazon-Backed Nuclear Startup X-Energy Files to Raise Up to $814M on Nasdaq
X-Energy, Inc. filed Amendment No. 3 to its Form S-1 on April 15, offering 42,857,143 Class A shares at $16-$19. The Rockville, Maryland-based advanced-reactor company expects to list under the symbol XE. It posted a $389.8 million net loss in 2025 on $109.1 million in revenue.
X-Energy, Inc. filed its third amended S-1 with the SEC on April 15, setting the stage for one of the largest advanced-nuclear IPOs to date.
The Rockville, Maryland-based developer of the Xe-100 high-temperature gas-cooled reactor is offering 42,857,143 shares of Class A common stock at an expected price of $16.00 to $19.00 per share. At the midpoint, the company estimates net proceeds of roughly $693.8 million. At the top of the range, the offering would raise approximately $814 million before underwriting discounts, and approximately $936 million if underwriters exercise their 30-day option to purchase an additional 6.4 million shares.
The stock will trade on Nasdaq under the ticker XE. ARK Investment Management and affiliates have indicated interest in purchasing up to $105 million of shares at the IPO price, according to the prospectus.
Who owns X-Energy
The offering will leave X-Energy, Inc. in an umbrella partnership-C-corporation (Up-C) structure holding 66.8% of X-Energy Reactor Company, LLC ("XERC"), the operating subsidiary. The remaining economic interest stays with pre-IPO holders, who receive Class B voting shares.
Amazon.com NV Investment Holdings LLC — a wholly owned subsidiary of Amazon.com, Inc. — holds more than 5% of the company's voting securities. The S-1/A values Amazon's existing position at approximately $284.6 million based on a $14.54 per-unit price. Ares Management is also a major investor, with two partners on the board; Segra Capital Management holds a separate 14 million-share block. X-Energy Holdings, LLC — the pre-IPO holding vehicle — retains 74.95 million common units of XERC, translating to a corresponding Class B voting stake in the public company.
The reactor and the customer pipeline
The Xe-100 is an 80-megawatt-electric small modular reactor that X-Energy says is intended to be deployed in a four-reactor "plant" configuration totaling 320 MWe. It uses HALEU-based TRISO pebble fuel manufactured by TRISO-X, LLC, a wholly-owned X-Energy subsidiary.
The company disclosed three anchor customers representing more than 11 gigawatts-electric and 144 reactors of pipeline across the United States and United Kingdom:
- Dow, the first customer to construct a reactor, is deploying a four-reactor Xe-100 plant at its Seadrift, Texas operations site. Under the Department of Energy's Advanced Reactor Demonstration Program, Dow is eligible to receive 50% of the cost to build that first four-pack.
- Amazon, through Energy Northwest, entered a Carbon Free Development and Funding Agreement for an initial four-reactor deployment in central Washington representing 320 MWe, with an option to expand to 960 MWe as part of a broader 5 GWe target. The arrangement gives Amazon a right of first refusal on a portion of X-Energy's scheduled delivery and a most-favored-nation pricing clause.
- Centrica, the largest UK energy services provider and a 20% owner of Britain's operating nuclear fleet, signed a Joint Development Agreement with X-Energy in September 2025.
X-Energy was one of two awardees in the DOE's Advanced Reactor Demonstration Program in December 2020, receiving an initial $1.2 billion commitment. The cooperative agreement provides 50/50 cost share of $2.4 billion in eligible project costs, and the company states it is "currently funded through at least August 2026 through a Continuation Application."
The financials
The prospectus shows a company with substantial cash on hand and rapidly widening losses.
| Fiscal year | 2024 | 2025 |
|---|---|---|
| Services revenue | $84.0M | $94.3M |
| Grant income | $36.2M | $14.8M |
| Total revenue | $120.2M | $109.1M |
| Operating expenses | $243.7M | $279.4M |
| Operating loss | ($123.5M) | ($170.3M) |
| Net loss | ($126.0M) | ($389.8M) |
Net loss more than tripled year-over-year while total revenue declined roughly 9%, driven by a $21 million drop in grant income. A $239.3 million charge in 2025 "other income (expense), net" — disclosed in the prospectus' summary financials table — accounts for the majority of the widening headline loss.
As of December 31, 2025, X-Energy reported $458.9 million in cash and cash equivalents, $304.9 million in short-term investments, and $261.5 million in long-term investments — a combined $1.025 billion liquidity cushion. Total assets were $1.21 billion against $369 million in liabilities and an accumulated deficit of $1.24 billion.
The Tax Receivable Agreement
As part of the IPO, X-Energy, Inc. will enter into a Tax Receivable Agreement with XERC and the pre-IPO holders. The agreement obligates the public company to pay 85% of certain future tax benefits to the selling legacy holders.
At the $17.50 midpoint, assuming all pre-IPO holders redeem or exchange their units immediately after the IPO, the TRA could aggregate to approximately $754.8 million over 15 years, according to the prospectus — a cash obligation that reduces proceeds available to the operating business.
Context
X-Energy becomes the second advanced-nuclear developer to pursue a major US listing, following Oklo's 2024 public-market debut. Unlike Oklo, which targets behind-the-meter microreactors, the Xe-100 is pitched as a grid-scale baseload asset aimed at industrial heat customers (Dow's Seadrift ethylene facility) and hyperscale data-center power (Amazon's Energy Northwest agreement).
No Xe-100 reactor has yet been built or licensed for commercial operation.