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Commonwealth Fusion Systems

Fusion energy company developing SPARC, a compact tokamak powered by high-temperature superconducting magnets 40× stronger than conventional designs.

ClimateUnited States·Founded 2018·ISO/NSO equity·cfs.energy ↗
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Source-audited Jun 12, 2026
Reference estimate only
4 methods · Source-audited Jun 12, 2026Low confidence (34%)

The four valuation methods disagree significantly (61.6× spread). Treat this as a wide reference range only — not a reliable point estimate.

$5.5B
wide range · ~$5B – ~$7B
Implied per-share: $20.6 · vs last primary +5%

No verified public secondary-market signal available for Commonwealth Fusion Systems. The estimate relies on last confirmed financing, peer multiples, sector momentum, and time decay.

Valuation basis:Last primary roundSource-audited Jun 12, 2026
Last primary round
$5.5B
Series B2 · 10mo ago
Secondary signal
—
No verified secondary signal

No verified public secondary signal is available. Hiive/Forge links are monitoring links only, not evidence of a current executable price.

Headcount
800
employees · LinkedIn+23%

LinkedIn count — directional proxy only. Historical figure sourced via Wayback Machine; treat ±15% as normal variance.

Revenue (est.)
$12M
annual run rate · est.

Complete company data

Every input we use, where we got it from, and how much we trust it.

✓

Source verification: CFS blog · confirmed by Bloomberg Aug 2025 · $5.5B Series B2 · manual-source-audit-2026-06

FieldValueConfidence
Company fundamentals
SectorClimatehigh
HeadquartersUnited Stateshigh
Founded2018high
Websitecfs.energyhigh
Last primary round
Post-money valuation$5.5Bhigh
Round nameSeries B2high
Date2025-08-27 (10 months ago)high
Lead investorTiger Global / Salesforce Ventureshigh
Amount raisedNot disclosedmedium
Capitalization
Total fully-diluted shares280Mlow
Implied share price (illustrative only)~$21low
Primary equity type grantedISO/NSOhigh
Financials
Annual revenue (est.)$12Mmedium
EV / Revenue (implied)458.3xmedium
Headcount
Employees (now)800medium
Employees (12 months ago)650medium
12-month headcount growth+23%medium
Methodology inputs
Sector ETF proxyICLNmedium
ETF annual return (trailing 3-yr)10%medium

Funding history

Primary rounds reported in Bloomberg, WSJ, TechCrunch, Reuters, or SEC Form D filings (efts.sec.gov). Linked per round below.

Valuation progression (equity rounds)
Valuation progression · equity rounds
$5.5Blatest · Series B2
Total growth
37×
Our estimate
$5.8B
$0.0B$1.7B$3.4B$5.1B$6.8BSeedSeries A$2.6BSeries BlatestSeries B2est.Est.
Primary round
Down round
Our estimate
Series B2+112%2025-08-27
$5.5B
Led by Tiger Global / Salesforce Ventures
Source: CFS blog · confirmed by Bloomberg Aug 2025 ↗
Series B+420%2021-12-01
$2.6B
Led by Tiger Global / Salesforce Ventures / Breakthrough Energy · raised $1.8B
Source: Bloomberg Dec 2021(historical ref.)
Series A+233%2018-09-01
$0.5B
Led by Khosla Ventures / Breakthrough Energy · raised $115M
Source: TechCrunch Sep 2018(historical ref.)
Seed2018-03-01
$0.2B
Led by The Engine (MIT) · raised $29M
Source: MIT News(historical ref.)

Secondary market signals

Secondary market signals: bid/ask/trade indications from Hiive (hiive.com), Forge Global, Caplight Index, and tender prices reported in the press.

No active listings found

We monitor Hiive, Forge Global, and EquityZen for Commonwealth Fusion Systems listings. As of July 2026, no verified secondary market activity has been recorded.

Secondary listings for private companies appear without announcement and typically close within days. When a listing appears, it often signals an upcoming tender offer or funding round.

Primary round history as valuation signal

In the absence of secondary market data, the funding history below is the primary valuation anchor. Method C (time-decay) uses this data to estimate current value.

Series B2 · 2025-08$5.5B
Series B · 2021-12$2.6B
Series A · 2018-09$0.5B

Get notified when a listing appears

Pro subscribers get notified within 2 hours when a secondary listing for Commonwealth Fusion Systems is detected. Most employees first hear about tender offers days after the market already knows.

Get listing alerts →

Check directly: Hiive ↗ · Forge Global ↗ · SEC Form D ↗

Public peer comparables

Public peer comparables: editorial selection of public companies with the closest business model. EV/Revenue and growth from public 10-Q filings and Bloomberg, refreshed quarterly.

TickerCompanyEV / Revenue
CWENClearway Energy, Inc.5.39x
ENPHEnphase Energy, Inc.4.05x
FSLRFirst Solar, Inc.4.45x
NEENextEra Energy, Inc.6.54x

Confidence breakdown

How much we trust each of the four valuation methods for this specific company, and why.

Method A — Peer-multiple
weight 25%suppressed23% confidence
↳ Effectively excluded from the blend — this method is structurally unreliable for this company.
Growth-weighted peer EV/Revenue: 5.9x → 35% private-company discount → 3.8x on $12M revenue. Output implies less than half the recent market anchor ($6B) — this company is likely valued on optionality / non-revenue factors and Method A is structurally less reliable here.
Method B — Secondary-implied
weight 45%suppressed25% confidence
↳ Effectively excluded from the blend — this method is structurally unreliable for this company.
No verified secondary market data available — estimate relies on primary round, peer multiples, and sector momentum.
Method C — Primary time-decay
weight 20%→ $6.2B68% confidence
$5.5B round (2025-08-27) × 1.17× growth × 0.96× multiple decay over 0.9 years
Method D — Sector momentum
weight 10%→ $6.0B47% confidence
$5.5B × (1 + 10% p.j.)^0.9yr = $6.0B via ICLN ETF-proxy
Overall confidence
34%
Weighted average of the four methods. Above 60% is high, 35–60% medium, below 35% low.
Low

Worked example for an employee

Illustrative mechanics only — this shows how the equity model works, not a reliable value estimate.

Illustrative mechanics only

This example shows equity mechanics only. It is not a reliable estimate of current value because model support is weak (confidence 34%, spread 61.6×).

Show illustrative values (not a reliable estimate) ▸
Profile: a hypothetical employee who joined Commonwealth Fusion Systems 24 months ago (2024-07-10) with 2,000 options, on the standard 4-year vesting schedule with a 1-year cliff.
Vesting
1,000 of 2,000
50% vested at month 24
Implied share price (mid)
$21
weighted average of 4 methods — low confidence
Gross vested value
$20,605
vested shares × implied price
Net value
$20,605
no strike, gross = net
Tax (rough)
$2,241
US federal only · AMT risk: low
What if the next round is…
Up round +30%
$23,293
New round at +30% valuation, 15% new shares issued
Down round −30%
$12,020
New round at −30% valuation, 20% new shares (higher dilution in distress)
Secondary today
$17,515
Sale on the secondary market at the typical 15% discount to the mid estimate
These illustrative values use the same calculation engine as the live calculator, but the underlying model is low-confidence for Commonwealth Fusion Systems. Use your own numbers as a starting point only. Try the calculator →

Transparent assumptions

What we assumed where exact data isn't available. If any of these don't match your situation, the numbers above will be off.

Fully-diluted share count
280M shares
We don't have authoritative cap-table access for private companies. The number above is reconstructed from SEC Form D filings, secondary-market price-vs-valuation math, and leaked share-class summaries. Actual fully-diluted count (including unvested option pool and SAFEs) may differ by 5–15%.
Common-stock waterfall
1.0× to common
We assume a clean common-stock outcome — i.e. preferred-share liquidation preferences and ratchets do not extract value before common. In a down-exit, this assumption can be very wrong: preferred stack can take 30–70% of proceeds.
Private-company illiquidity discount
35% off public peers
Applied to Method A (peer-multiple). Per-company because category leaders with deep secondary markets and a clear IPO path warrant a smaller discount than early-stage names. The literature range is 10–35%; for Commonwealth Fusion Systems we use 35% based on secondary-market depth, valuation history, and proximity to liquidity.
Revenue growth assumption (Method C)
20% YoY
Compounded forward from the last primary date to today to estimate the company's value drift. Set per-company based on disclosed or reported ARR trajectory. Method C is further capped at 1.3× the most recent secondary trade (if any) to stop runaway extrapolation when revenue growth outpaces what the market is actually paying.
Sector ETF momentum (Method D)
ICLN @ 10%/year
Method D applies the trailing return of ICLN as a market-proxy adjustment to the primary valuation. Crude — meant as a tiebreaker when peer and secondary data conflict, not as a primary signal.
Outlier auto-downweight
Methods >50% from median get ½ weight
Robust-statistics safety net: any method whose output strays more than 50% from the median of the other three methods has its confidence weight halved when computing the blended mid-point. Prevents a single bad extrapolation from dragging the headline.
Recency decay for secondary trades
180-day half-life (e⁻ᵈ/¹⁸⁰)
A trade from 30 days ago counts ~5× more than one from 180 days ago. Tunable; some platforms use shorter half-lives.
Tax estimate
US federal only, single filer
Uses 2024 US federal brackets, ignoring state tax, NIIT, AMT credit recovery, and any other deductions. Treat as a directional sanity check, not a tax bill.
All data from public sources. Not investment, tax, or legal advice. Not affiliated with Commonwealth Fusion Systems. Last refreshed manually — see methodology for our update cadence.