Helion Energy
YC S14 ↗Seattle, US · Founded 2013 · Delaware corporation · 150 employees · 8 known investors
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.
Advanced ManufacturingCleantechClimate TechDeep TechEnergyHardwareFusion EnergyHard TechClimatein /helion-energy/@helion_energyycombinator.com ↗
Founders & leadership· Y Combinator alumni (S14)
Investors · 8
Reported raises · per SEC filings
Form D private placements▶$10.6MraisedJul 2015 · 6 investors · OtherRule 506(b)
▶$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
Source: SEC EDGAR Form D. Amounts as filed; amended filings shown once at their latest values.
In the news
- Fusion roundup: Helion sets temperature record; Inertia raises $450M -- ANS / Nuclear Newswireans.org · 2026
- Fusion Energy Attracts $4.5 Billion in a Year; General Fusion Surges on Second Day of Nasdaq Trading — BigGo Financefinance.biggo.com · 2026
- Helion Energy Raises $425 Million to Build World's First Nuclear Fusion Power Plant - London Dailylondondaily.com · 2026
- Helion's $465M Raise: Inside the Fusion Energy Betangelinvestorsnetwork.com · 2026
- Helion Raises $465 million in Latest Funding Roundthefusionreport.substack.com · 2026
- Helion, the Sam Altman-backed fusion startup, raises $465M to build a power plant for Microsoft | TechCrunchtechcrunch.com · 2026
- Helion Stock Pre-IPOnasdaqprivatemarket.com · 2025
- Helion raises $425M to help build a fusion reactor for Microsoft | TechCrunchtechcrunch.com · 2025