Who are Helion Energy's investors?

Helion Energy's investors include Anti, BoxGroup, Congruent Ventures, SoftBank Group, SoftBank Vision Fund, Y Combinator, Capricorn Investment Group, Fontinalis Partners and 8 more.

How much funding has Helion Energy raised?

Helion Energy has disclosed $477.1M raised across 3 of its 6 known rounds.

Where is Helion Energy headquartered?

Helion Energy is headquartered in Seattle, US.

Helion Energy

YC S14

Seattle, US · Founded 2013 · Delaware corporation · 150 employees · 18 known investors

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Helion develops fusion energy systems designed to generate clean electricity for commercial use. The company builds pulsed magnetic fusion prototypes with applications for industrial and commercial electricity generation.

Also known as Helion

Advanced Manufacturing Cleantech Climate Tech Deep Tech Energy Hardware Fusion Energy Hard Tech ClimateUnited States of AmericaAmerica / Canada

Founders & leadership· Y Combinator alumni (S14)

Helion Energy was founded in 2013 by David Kirtley, Chris Pihl, John Slough, George Votroubek, and Anthony Pancotti.

David Kirtley Founder and CEOFounder and CEO of Helion Energy, a privately funded company developing fusion energy systems—pulsed magnetic fusion prototypes—to generate clean electricity for commercial and industrial use.

Chris Pihl Co-Founder, CTOCo-founder and CTO of Helion Energy, which develops pulsed magnetic fusion systems to generate electricity for commercial and industrial use.

John SloughChief Scientistformer

George Votroubek FounderCo-founder and Chief Scientist of Helion Energy, which develops pulsed magnetic fusion systems for commercial and industrial electricity generation.

Anthony Pancotti Co-FounderCo-founder of Helion Energy, which develops pulsed magnetic fusion prototypes aimed at generating clean electricity for industrial and commercial use.

Board

Sam Altman Board directorCo-founder & CEO of OpenAI; former President of Y Combinator

Ajay Royan Board directorInvestor at Mithril Capital Management

Investors · 18

Antilisted by AntiSan Juan · $250K – $30M

BoxGrouplisted by BoxGroupNew York · $250K – $1M

How we know: boxgroup.com · Not right? Tell us

Congruent Ventureslisted by Congruent VenturesSan Francisco · $100K – $5M

How we know: Congruent Ventures's portfolio page · Not right? Tell us

SoftBank Grouplisted by SoftBank GroupTokyo

How we know: SoftBank Group's portfolio page · Not right? Tell us

SoftBank Vision Fundlisted by SoftBank Vision FundLondon

How we know: visionfund.com · Not right? Tell us

Y Combinatorlisted by Y CombinatorSan Francisco · $500K

How we know: the Y Combinator directory · open dataset · 5k.vc investor directory · Not right? Tell us

Capricorn Investment GroupreportedNew York

How we know: Wikidata · techcrunch.com · Y Combinator's founder network · Not right? Tell us

Fontinalis PartnersreportedDetroit · $250K – $5M

How we know: a partner's Signal profile · Not right? Tell us

Good Venturesreported

How we know: Y Combinator's founder network · Not right? Tell us

Lightspeed Venture PartnersreportedMenlo Park · $1M – $5M

How we know: techcrunch.com · open dataset · 5k.vc investor directory · Not right? Tell us

Lux CapitalreportedNew York · $100K – $100M

How we know: a partner's Signal profile · Not right? Tell us

Mithril Capital ManagementreportedAustinvia Ajay Royan · board

How we know: a partner's Signal profile · board seat on SEC Form D · techcrunch.com · the VCSheet dataset · open dataset · 5k.vc investor directory · Y Combinator's founder network · Not right? Tell us

Paragon PartnersreportedMünchen

How we know: Y Combinator's founder network · Not right? Tell us

Sam Altmanreported

How we know: Wikidata · Y Combinator's founder network · Not right? Tell us

Technology ImpactreportedPalo Alto

How we know: Y Combinator's founder network · Not right? Tell us

Thrive CapitalreportedNew York · $500K – $25M

How we know: funding news · open dataset · 5k.vc investor directory · Y Combinator's founder network · Not right? Tell us

Also in the syndicate · 2

NucorSoftBank Vision Fund 2

Funding

SEC filings, press & company announcements

$477.1M disclosed across 3 of 6 rounds · 2014–2026

Undisclosed amountSeries GJun 2026
Source ↗
$465MraisedJun 2026 · 3 sources
Source ↗
Undisclosed amountSeries FJan 2025
Capricorn Investment Group, Lightspeed Venture Partners, Mithril Capital, Nucor, SoftBank Vision Fund 2
Source ↗

▶$10.6MraisedJul 2015 · 6 investors · Other

Rule 506(b)

Officers, directors & promoters on the filing

John SloughExecutive Officer, Director
Christopher PihlExecutive Officer, Director
Sam AltmanDirector
Ajay RoyanDirector
David KirtleyExecutive Officer, Director

Offering amount: $21.2M
Amount sold: $10.6M
First sale: Jun 2015
Incorporated: Corporation, Delaware, 2013
Federal exemptions: 06b

Full filing on SEC EDGAR ↗

▶$1.5MraisedAug 2014 · 3 investors · Other

Rule 506(b)

Officers, directors & promoters on the filing

Christopher PihlExecutive Officer, Director
John SloughExecutive Officer, Director
Ajay RoyanDirector
David KirtleyExecutive Officer, Director

Offering amount: $1.5M
Amount sold: $1.5M
First sale: Jul 2014
Incorporated: Corporation, Delaware, 2013
Federal exemptions: 06b

Full filing on SEC EDGAR ↗

Source: SEC EDGAR Form D. Amounts as filed; amended filings shown once at their latest values.

Founder mafia

3 people who came through Helion Energy went on to found or lead other companies.

Sam AltmanDirectorFounded Tools for Humanity +3 Alex KolicichInvestorFounded 8VC Chris PihlCTOFounded Sigma Genetics

Related companies · 6

OkloOklo develops next-generation fast fission reactors for producing clean electricity at scale, with a focus on safety features and the ability to use recycled nuclear waste as fuel. The company's Aurora reactor is designed to generate up to 75 megawatts of electrical power.

Maritime FusionMaritime Fusion designs and builds zero-emission fusion reactors for deployment in maritime transport and remote energy installations. The company aims to use these off-grid applications as a pathway to develop cost-competitive grid-scale fusion reactors.

Zephyr FusionZephyr Fusion develops compact, in-orbit fusion power systems for space-based applications including microgravity manufacturing, data centers, defense, propulsion, and human habitation. The company leverages fusion technology to provide megawatt-class power generation for space industry customers.

AirthiumAirthium manufactures high-temperature industrial heat pumps that reach up to 550°C and operate in hybrid mode, switching between electricity and gas to optimize cost and carbon emissions. The system is designed for industrial process heat applications requiring reliable 24/7 operation in the 150–550°C range.

EnodeEnode provides APIs that enable energy companies and climate tech startups to coordinate electricity demand and supply by automatically optimizing consumer energy usage based on renewable availability and pricing. The platform manages consumption across over 250 million energy customers globally and supports 1000+ energy devices spanning 80+ brands.

FFuse Energy develops fusion energy technology, with work spanning hardened electronics and radiation testing (HEART) and recycling of radioactive waste, aiming to provide an on-demand clean energy source. It brings together a team across engineering, fusion science, energy policy, and manufacturing.

Companies working in the same space as Helion Energy.

Legal entities · 1

corporate structure

Helion Energy, Inc.

In the news

Helion, the Sam Altman-backed fusion startup, raises $465M to build a power plant for Microsoft | TechCrunchtechcrunch.com · Jun 2026

Helion raises $425M to help build a fusion reactor for Microsoft | TechCrunchtechcrunch.com · Jan 2025

Helion secures $2.2B to commercialize fusion energy – TechCrunchtechcrunch.com · Nov 2021

Frequently asked questions

What does Helion Energy do?: Helion develops fusion energy systems designed to generate clean electricity for commercial use. The company builds pulsed magnetic fusion prototypes with applications for industrial and commercial electricity generation.
Who founded Helion Energy?: Helion Energy was founded by David Kirtley, Chris Pihl, John Slough, George Votroubek, Anthony Pancotti in 2013.
Who are Helion Energy's investors?: Helion Energy's investors include Anti, BoxGroup, Congruent Ventures, SoftBank Group, SoftBank Vision Fund, Y Combinator, Capricorn Investment Group, Fontinalis Partners and 8 more.
How much funding has Helion Energy raised?: Helion Energy has disclosed $477.1M raised across 3 of its 6 known rounds.
Where is Helion Energy headquartered?: Helion Energy is headquartered in Seattle, US.