Fusion energy startup backed by Sam Altman pursuing direct-electricity-conversion power
Energy📍 Everett, WAFounded 2013
Current Valuation
$5.4B
as of 2024-Q4
UNICORN
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.
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 7mo 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
—
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.