Commonwealth Fusion Systems Stock for Accredited Investors

Climate Tech
CEO Bob Mumgaard Founded 2018 HQ Cambridge, Massachusetts, US

Commonwealth Fusion Systems is a private fusion energy company developing high-temperature superconducting magnet technology to enable compact fusion power plants. It aims to commercialize clean, abundant electricity and is pursuing the SPARC and ARC reactor designs.

Access to pre-IPO shares is available to accredited investors through UpMarket.

Latest Price
Previous Price
Series B 2021

How to Invest in Commonwealth Fusion Systems Through UpMarket

Commonwealth Fusion Systems shares are not on public exchanges. UpMarket provides accredited investors access through secondary market transactions.

Step 01

Verify accredited investor status

Confirm eligibility under SEC Rule 501 of Regulation D. Income or net worth threshold applies.

Step 02

Create an UpMarket account

Complete KYC/AML onboarding. Typically 1–2 business days. Licensed rep assigned on signup.

Step 03

Review available Commonwealth Fusion Systems offerings

Full offering memoranda and risk disclosures provided before any commitment is required.

Step 04

Complete subscription documents

Review and sign subscription agreement. All documents handled digitally through the platform.

Step 05

Fund your investment

Wire transfer or ACH. $50K minimum. Funds held in custodial account until close.

Pre-IPO investments are illiquid, speculative, and involve risk of total loss of capital.

$1.3B+
UpMarket has brokered over $1.3 billion in alternative investments*
*Includes principal invested and appreciation of investments originated via the UpMarket platform based on historical trade volume and valuation estimates through March 31, 2026. Of the total, approximately $301 million is managed by UpMarket Management, with the remaining originated investments managed by affiliates. Past performance is not predictive of future results.

Valuation Growth Over Time

Post-money valuation by round
Previous rounds Most recent
DateRoundPPS (split-adj.)Valuation
Aug 2025 Series B2
2021 Series B
May 2020 A2

Commonwealth Fusion Systems Revenue and Growth

Annual revenue

Why Investors Are Watching Commonwealth Fusion Systems

Growth Signal

CFS raised $863M in 2025, lifting total capital to $3B

CFS announced an $863 million Series B2 round in August 2025, calling it the largest raise among deep tech and energy companies since its 2021 Series B. The company said the new round brought total capital raised to about $3 billion, roughly one-third of all private fusion funding.

Competitive Moat

CFS says it has raised more capital than any fusion peer

CFS says it has raised over $2 billion in capital, more than any other fusion energy company, and that it has attracted top talent to design commercial fusion power. Its 2021 Series B alone exceeded $1.8 billion, with backers including Google, Breakthrough Energy Ventures, and Bill Gates.

Market Opportunity

CFS targets first commercial fusion power in a massive energy market

In its August 2025 financing announcement, CFS said it is moving closer to being the first company in the world to commercialize fusion power. The company positions fusion as a scalable clean-energy source for global electricity demand, with support from major investors including NVIDIA's NVentures and a consortium of 12 Japanese companies.

Interested in Commonwealth Fusion Systems stock? Fill out the form above or sign up directly. Subject to availability. Accredited investors only.

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Commonwealth Fusion Systems Leadership Team

Robert Mumgaard
CEO
Ally Yost
Chief of Staff
Dan Brunner
CTO

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Commonwealth Fusion Systems Stock FAQ

No. As of March 2026, Commonwealth Fusion Systems is a private company and does not trade on any public stock exchange. Accredited investors can access Commonwealth Fusion Systems shares through UpMarket, a FINRA-registered broker-dealer that specializes in pre-IPO investments.

Commonwealth Fusion Systems does not have a public stock price because it is privately held. The most recent known share price comes from its last funding round. Pre-IPO share prices on the secondary market may differ from the last round price depending on supply, demand, and market conditions.

Yes. Accredited investors can indicate interest in Commonwealth Fusion Systems shares through UpMarket by filling out the form on this page or creating an account at upmarket.co. All pre-IPO offerings are subject to availability and require a $50,000 minimum investment. UpMarket is a FINRA-registered broker-dealer and has brokered more than $500M in alternative investments since 2019.

Pre-IPO investments carry significant risks. Commonwealth Fusion Systems shares are illiquid, meaning there is no public market to sell them quickly. There is no guaranteed exit timeline or return. The investment is speculative in nature, and investors should be prepared for the possibility of total loss. Valuations of private companies can fluctuate substantially between funding rounds. Investors should consult their financial advisor and review all offering documents before investing.

In a pre-IPO transaction, accredited investors purchase shares from existing shareholders (such as employees, early investors, or other holders) through secondary market platforms. The company itself does not issue new shares in these transactions. UpMarket facilitates these trades as a FINRA-registered broker-dealer, handling compliance, documentation, and settlement on behalf of both parties.

There are two primary exit paths for pre-IPO holdings: selling your shares on the secondary market to another buyer, or holding until the company completes an IPO or is acquired. Both paths are subject to transfer restrictions, company approval (right of first refusal), and market conditions. The timing of any exit is unpredictable, and investors should plan for a multi-year holding period.

The minimum investment for most pre-IPO offerings on UpMarket is $50,000. This amount may vary depending on the specific offering and share availability. There are no fees to create an UpMarket account or browse available investments. Investors only pay transaction-related fees when they complete an investment.

UpMarket's valuation estimate of is derived from a proprietary model that incorporates multiple data sources: funding round data (Caplight), revenue estimates (Sacra), secondary market pricing, and public company comparables. The model applies a private company discount to the public comp multiple to account for illiquidity and information asymmetry. This estimate is not investment advice and may differ substantially from the price at which shares actually trade.

Commonwealth Fusion Systems develops compact fusion power plants using high-temperature superconducting magnets and generated $31.7M in 2026 revenue, after raising $863M in 2025 to bring total capital to $3B — accredited investors can access Commonwealth Fusion Systems stock through UpMarket.

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