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Helion Energy

Everett, WA, United States Energy Private

Helion Energy is a private fusion energy company developing commercial-scale fusion power plants using magneto-inertial fusion technology. The company targets deployment of its first commercial facility by 2028 and has a power purchase agreement with Microsoft for 50 MWe of electricity. Founded by David Kirtley, John Slough, Chris Pihl, and George Votroubek, Helion is backed by Sam Altman and has raised over $1 billion in funding.

Overview

Company data and valuation marks are estimates and may be incomplete, stale, erroneous, or revised.

Founded

2013

Employees

145–155

Total Funding

$1.47B

8 rounds

Latest Valuation

$5.4B

June 4, 2026

Funding

Total raised $1.47B across 8 rounds

Funding data and valuation marks are estimates and may be incomplete, stale, erroneous, or revised.

Last updated 06-25-2026

Latest Round

Type

Series G

Date

June 4, 2026

Amount

$465M

Valuation

$15.5B

Lead Investors

Thrive Capital
DateRoundAmount RaisedValuationLead Investors
June 4, 2026 Series G $465M $15.5B Thrive Capital
January 1, 2025 Series F $425M $5.4B Lightspeed Venture Partners, SoftBank Vision Fund 2
November 1, 2021 Series E $500M $3B Sam Altman

Funding by Round

Funding data and valuation marks are estimates and may be incomplete, stale, erroneous, or revised.

Valuation Trajectory

Valuation indexed to 1.0× at the selected entry round. Valuation marks are estimates and may contain errors. Hover each dot to compare.

If you invested at:
1x 2x 5x 10x 20x 2016 2019 2022 2025 Helion Energy

Entry · Series A

$0.8B

Aug 2014

Helion Energy today

$15.5B

Jun 2026 · latest mark

Helion Energy multiple

18.2x

valuation uplift since first round

Y-axis is logarithmic. Hollow dots = estimated valuations. Does not represent realized investor returns.

Prominent Investors

Lightspeed Venture Partners SoftBank Vision Fund 2 Sam Altman Capricorn Investment Group Mithril Capital Dustin Moskovitz Nucor

Leadership

  • David Kirtley

    Founder & Chief Executive Officer

    LinkedIn
  • Chris Pihl

    Co-Founder & Chief Technology Officer

  • George Votroubek

    Co-Founder & Principal Scientist

  • Pragav Jain

    Chief Financial Officer

  • Sachin Desai

    General Counsel

  • Savanna Thompson

    Chief Business Operations Officer

Competitors

Competitor list is illustrative and may be incomplete, stale, or erroneous.

  • Commonwealth Fusion Systems

    Tokamak-based fusion company developing SPARC pilot plant targeting net fusion energy by late 2026, with ARC commercial plant planned for Virginia starting 2027-2028. Backed by MIT and major institutional investors.

  • TAE Technologies

    Aneutronic hydrogen-boron fusion company using beam-driven approach. Competing on timeline with goal to manufacture prototype commercial reactor by 2030.

  • Tokamak Energy

    UK-based private fusion company developing spherical tokamak fusion reactors. Advancing high-temperature superconducting magnet technology for commercial fusion.

  • Type One Energy

    Stellarator-based fusion company focused on advanced magnetic confinement fusion technology for commercial power generation.

Helion Energy Investment FAQ

Public status and buying access

No. Helion Energy is a private company and does not have a public stock ticker or trade on a public stock exchange. Its shares are generally held by founders, employees, investors, and other private shareholders. Buyers and sellers may be able to transact in Helion Energy shares through private secondary transactions, but any transaction depends on share availability, buyer and seller agreement, transfer restrictions, company approval rights, and any applicable right of first refusal. There is no guarantee that Helion Energy will complete an IPO or other liquidity event.

Yes, it is sometimes possible to buy Helion Energy shares pre-IPO through private secondary transactions. This depends on finding a willing seller, company approval, and satisfying any transfer restrictions or rights of first refusal.

Buyers interested in buying Helion Energy shares on the secondary market typically do so through SetterVC and other secondary-market platforms, subject to eligibility requirements, share availability, transfer restrictions, and issuer approval. Buyers may need to satisfy sophistication, accreditation, institutional, platform, regulatory, or other eligibility requirements before participating. Once eligible, buyers may be able to view listings, make bids, and work with a licensed broker through the transaction process. Buyers should ensure they have appropriate legal and financial advisors guiding them before completing any transaction.

The company's latest round valuation was approximately $5.4B as of June 4, 2026. The latest round valuation is often used as one reference point in secondary-market pricing, but secondary prices may be above or below that valuation at any given time. Secondary pricing can shift significantly based on post-round conditions, such as changes in company performance, supply-demand dynamics, share class, transaction size, transfer restrictions, or broader market shifts. Any implied valuation from a past round should be confirmed with a broker or through live market listings before relying on it.

Valuation and funding

Helion Energy was most recently valued at approximately $5.4B as of June 4, 2026. This is a private valuation and may differ from secondary pricing. Secondary shares may trade above or below this mark based on various factors. SetterVC and Setter Capital does not verify the accuracy of these valuations. Buyers and sellers should always confirm current valuations before completing any transaction.

Helion Energy's valuation has changed over time based on funding rounds, tender offers, secondary-market indications, and other reported or collected valuation marks. Helion Energy's valuation moved from approximately $850M as of August 1, 2014 to approximately $15.5B as of June 4, 2026. This comparison reflects company-level valuation marks and does not represent realized investor returns. Secondary-market prices may differ from these valuations based on share class, transaction size, transfer restrictions, supply and demand, company performance, and broader market conditions. SetterVC and Setter Capital does not verify the accuracy or completeness of valuation data, and buyers and sellers should confirm current information before relying on it.

Helion Energy's latest disclosed funding round was a Series G round in June 4, 2026. The round raised approximately $465M at an approximately $15.5B valuation, with Thrive Capital listed as disclosed lead or major investors. Primary funding rounds are different from secondary transactions: in a primary round, capital goes to the company, while in a secondary transaction, investors buy existing shares from current shareholders. Funding-round data reflects publicly reported or collected information and may be incomplete. The latest round valuation should be confirmed before it is used as a pricing reference.

Helion Energy has raised approximately $1.47B in disclosed funding across 8 rounds. These figures reflect primary capital raised by the company and do not include every possible secondary transaction, undisclosed round, debt facility, or private transfer. Reported funding totals can change as new rounds are announced or older round details are corrected. Eligible users can use SetterVC to track Helion Energy's funding history alongside private-market activity where available.

Helion Energy's disclosed investors include Lightspeed Venture Partners, SoftBank Vision Fund 2, Sam Altman, Capricorn Investment Group, Mithril Capital and Dustin Moskovitz. Investor lists are based on public reporting, company announcements, and collected funding-round data, and may be incomplete. Participation in a prior funding round does not mean those investors are currently buying or selling shares. On SetterVC, eligible users can review Helion Energy's funding history, valuation history, and private-market activity alongside other venture-backed companies.

Market context

Helion Energy's most-cited competitors include Commonwealth Fusion Systems, TAE Technologies, Tokamak Energy and Type One Energy. Investors often compare these companies by sector, product focus, valuation, funding raised, growth signals, investor base, and private-market activity.

Secondary-market demand for Helion Energy shares can be affected by company performance, revenue growth, profitability, funding history, valuation, investor interest, sector momentum, public-market conditions, expected timing of a liquidity event, and the availability of shares for sale. Demand can also be affected by transfer restrictions, company approval rights, right of first refusal processes, limited information, and the price expectations of buyers and sellers. Strong demand does not guarantee strong pricing, liquidity, or investment returns. Weak demand does not necessarily reflect the company's long-term prospects. Demand signals should not be treated as a recommendation or prediction of investment performance. Buyers and sellers should treat demand signals as informational and conduct their own diligence before transacting.

Selling and transaction mechanics

Sellers often rely on intermediaries and platforms, such as SetterVC and other secondary-market platforms, to identify potential buyers. The exact process varies by company and transaction, but sellers often begin by confirming their ownership, desired price, transferability, and any company approval or notice requirements. If the seller agrees with a buyer on acceptable price and terms, the company may need to be notified through a share transfer notice or similar process. If a right of first refusal, company approval right, or other transfer restriction applies, the seller may need to wait until that process is completed. The parties may then execute a purchase and sale agreement, complete required transfer documentation, and close if all required conditions are satisfied. Sellers should always seek proper legal and financial advice before completing the transaction.

Yes, current and former Helion Energy employees, early investors, and other existing shareholders may be able to sell vested shares before an IPO through a private secondary sale. This is not automatic; it depends on whether the shareholder has transferable shares, whether there is buyer demand, and whether the company's governing documents permit the transfer. Many companies require prior notice, company approval, or a right of first refusal before shares can be sold. Sellers should also seek proper legal and financial advice before proceeding.

A Helion Energy secondary transaction usually involves an existing shareholder selling shares to a buyer before a public listing. The buyer and seller typically agree on price, number of shares, share class, and closing conditions. The seller may then need to notify Helion Energy through a share transfer notice or similar process. If Helion Energy or existing investors have approval rights, transfer restrictions, or a right of first refusal, those steps may need to be completed before the transfer can close. The parties typically enter into a purchase and sale agreement, complete any required transfer documentation, and close only if the necessary conditions are satisfied. Timing and certainty can vary by company and transaction.

In most private secondary transactions, parties commonly use a purchase and sale agreement that outlines price, terms, and conditions. They may also use share transfer documentation, often a stock transfer notice, share transfer notice, transfer instruction, or similar document, along with any required company approval or right of first refusal materials. Proof of ownership, such as a cap table entry, share certificate, brokerage statement, issuer confirmation, or administrator confirmation, may also be important. Buyers often request recent company financials, but private companies may limit disclosure. Since every deal varies, buyers and sellers should consult legal and financial advisors to understand which documents are needed.

Risk, diligence, and investor caution

Buying Helion Energy shares pre-IPO is risky. Shares are illiquid, no IPO or liquidity event is guaranteed, valuations can change, transfers may require company approval, and private companies may provide limited financial disclosure. Be prepared for total loss. SetterVC and Setter Capital do not provide due diligence, legal, tax, accounting, valuation, or investment advice. Buyers must conduct their own due diligence, verify information, and seek independent legal and investment advice before proceeding.

Private secondary shares are typically illiquid. Unlike public stocks, there is no active public market, so selling them can be difficult and time-consuming. Sales depend on finding a willing buyer and often require company approval. Investors should be prepared to hold the shares for an extended period, with no guarantee of a future sale. Always assess your need for liquidity before investing.

SetterVC and Setter Capital do not provide due diligence, legal, tax, accounting, valuation, or investment advice. Buyers must conduct their own due diligence, including verifying ownership, transferability, legal structure, company approval, and assessing the company's prospects. SetterVC and Setter Capital do not provide advice on whether an investment is good, what price to pay, or what the best bid or ask is. SetterVC and Setter Capital may share documents in some circumstances, but it does not guarantee their accuracy or completeness. Due diligence is essential. Seek legal and investment advice as needed.

Before buying Helion Energy shares, a buyer should try to review the share class, price per share, implied valuation, transfer restrictions, ROFR process, company approval rights, seller ownership evidence, recent financing or tender-offer information, available financial information, information rights, resale restrictions, tax considerations, and expected liquidity paths. Not all information may be available for a private company. Buyers should confirm available diligence, process details, and information needs with their own legal, tax, and investment advisers.

SPVs carry risks. Examples include the need to confirm the company allows SPV-based transfers, verify that the SPV truly owns the shares or interests it claims to own, and ensure it has not sold more interests than it holds. Due diligence is essential. Seek legal and investment advice as needed.

Forward contracts carry risks. Examples include the seller refusing to transfer the shares at the future date, even if the seller owns them, the seller going bankrupt with creditors claiming the shares, or the seller committing the same shares to multiple parties. Due diligence is essential. Seek legal and investment advice as needed.

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