Fusion energy startup backed by Sam Altman pursuing direct-electricity-conversion power
Helion is developing a pulsed magneto-inertial fusion reactor that captures electricity directly from expanding plasma without a steam turbine. Signed a 50 MW power purchase agreement with Microsoft, promising delivery by 2028. Sam Altman is the chairman and largest individual investor.
Energy📍 Everett, WAFounded 2013
Current Valuation
$5.4B
as of 2024-Q4
UNICORN
QL Price
$19B
+23% vs last round
QuantLogix's current estimate for Helion Energy, published 2026-10-07 — above the last disclosed round of $16B (2026-06).
Confidence
medium
Basis
secondary led
What backs this price
Last disclosed round
$16B
2026-06
weight 0.78
Secondary market print
$24B
2026-06-27
weight 0.54
How this price has held up
No round has priced for Helion Energy since QuantLogix began publishing a price for it, so there is nothing to grade yet. The claim above is on the record from 2026-10-07 and will be graded against the next priced round. See the full accuracy record →
Which publicly-traded funds already hold it, what $10,000 buys, and whether any route is open to you.
Cite this price as QuantLogix QL Price, Helion Energy, 2026-10-07 (680e7679d9ae0476).
The id pins this exact claim, so a citation stays checkable after the price moves.
Model estimate for research — not a quote, target price, or investment advice.
IPO Outlookprivate
Is Helion Energy going public?
No. Helion Energy has no imminent IPO plans on record. It is still private.
What is Helion Energy's valuation in 2026?
Helion Energy is valued at $5.4B as of 2024-Q4, set by its Series F ($425M, Jan 2025). That is the last confirmed mark, not a live price — private shares do not trade continuously.
Has Helion Energy filed an S-1?
No public S-1 is on file for Helion Energy.
Who are Helion Energy's investors?
Helion Energy's investors include Sam Altman, Mithril Capital, Capricorn, Dustin Moskovitz, Reid Hoffman, SoftBank.
How much has Helion Energy raised?
Helion Energy has raised $1.0B in total, most recently a Series F of $425M in Jan 2025.
Is Helion Energy publicly traded — can you buy Helion Energy stock?
No. Helion Energy is a private company — its shares are not listed on any exchange and there is no ticker. The routes to exposure are pre-IPO secondary marketplaces and funds (accredited investors), employee tender offers when the company runs one, and public companies with read-through exposure. QuantLogix maps every route it can verify for Helion Energy on its Pre-IPO Access Desk.
Answers are derived from the roster record shown on this page — filing status, last round and confirmed marks. Where the record is silent, the answer says so rather than guessing.
Company Profile
CEO
David Kirtley
Founded
2013
HQ
Everett, WA
Employees
~250
Total Raised
$1.0B
Last Round
Series F — $425M (Jan 2025) · Lead: SoftBank
IPO Status
no imminent plans
Fundraising Status
Series F · $425M · 1y 9mo ago
no imminent plansTotal raised $1.0B
Secondary Market
Implied price / share
$65
Last round price / share
$41.81
vs last round
+55.5%
Last round price vs secondary price
Secondary price return by period
Implied per-share price from private secondary transactions, as of Jun 2026. This is a point estimate, not a quote — the feed carries no bid, ask or spread, and a secondary print is evidence of what someone paid on that date rather than a live market. Compare across every tracked name →
Latest Funding Round
Round
Amount
Date
Lead Investor
Post-Money
Series F
$425M
Jan 2025
SoftBank
—
Talent Signal
Hiring trend
▼ Hiring downtrend
-37% vs 2026-08
Open roles
68
via ashby
Product-build share
78%
engineering, research, product, design
Trajectory
tightening
heavy product build — 78% of open roles are product-building functions (engineering/research/product) — 23 of 68 open roles are hardware.
Open roles trending down; no tracked executive churn.
Open roles by month
Open roles by function
■ product-building ■ go-to-market / G&A
R&D Hardware Test & Development ManagerSenior Electrical EngineerSenior Power Electronics EngineerPrincipal Experimental ScientistPrincipal Nuclear Materials EngineerTechnical Program Manager - HERCULES
Counted from Helion Energy's live job board as of 2026-09-15; role functions classified from posting titles. Open-role counts are an activity signal, not headcount. Refreshed monthly.
Founders & Key People
David KirtleyGeorge VotroubekJohn SloughChris Pihl
Investors
Sam Altman · Mithril Capital · Capricorn · Dustin Moskovitz · Reid Hoffman · SoftBank
Products
Polaris (7th-gen prototype)
Orion (8th-gen, planned for power delivery)
Competitors
Commonwealth Fusion · TAE Technologies · Tokamak Energy
FusionEnergySam AltmanDirect Energy Conversion
Private-company numbers are not real-time. Reflects publicly disclosed valuations from press releases, news reports, and tender offers as of 2024-Q4. Refreshed quarterly.