
Company
Helion Energy
- Energy
- Latest funding:
- $425M · Series C+ · Dec 2025
Overview
Builds and tests fusion systems, prototypes, and a planned power plant to demonstrate electricity generation for future commercial energy customers.
Part of the Seattle ecosystem
Related
Amazon Web Services AI Infrastructure ($AMZN)Deploys managed, dedicated AI infrastructure and accelerated EC2 compute for organizations training or running large models on proprietary data under sovereignty and security requirements.
Avalanche EnergyDevelops compact fusion machines and alpha-voltaic nuclear battery technology for clean power generation, neutron applications, materials testing, space science, defense, and mobile energy uses.
Breakthrough Energy VenturesInvests in and helps build clean energy businesses, partnering with technology developers to reduce emissions across electricity, manufacturing, agriculture, transportation, and buildings.
Electric EraBuilds EV fast charging stations and software for retailers, fuel sellers, restaurants, system integrators, and data centers managing site deployment and power capacity needs.
Group14 TechnologiesDevelops and manufactures silicon anode materials for rechargeable batteries, offering SCC55 as a graphite replacement for cell makers in electric mobility, storage, electronics, defense, and aerospace.
Hemisphere VenturesInvests in companies and maintains a portfolio of invested businesses, providing capital to support company growth across selected business opportunities.
InterluneDevelops lunar infrastructure for site preparation, construction, material processing, resource harvesting, and cargo return for commercial and government space customers.
ModumetalDevelops and manufactures nanolaminated alloys grown onto base metals, producing NanoGalv materials for industrial applications needing stronger, more durable metals.
Monolithic Power Systems ($MPWR)Power-management semiconductors for AI servers, data centers, robotics, and industrial electronics. Public via $MPWR (NASDAQ). Kirkland WA HQ.
TerraPowerDevelops advanced nuclear energy systems and radioisotope extraction processes for carbon-free power, grid needs, industrial decarbonization, and medical cancer treatment applications.
TassoBuilds home diagnostic blood collection devices that help patients and clinicians support virtual care, frequent monitoring, and more informed healthcare decisions without traditional needle draws.
XanfabBuilds mission-critical circuit card assemblies, PCB assemblies, precision lead-formed components, and electro-mechanical products for aviation, space, and defense manufacturing needs.
Timeline
Funding Roundbloomberg.com ↗
Series F; Polaris pulsed fusion device + 50 MW Microsoft offtake.