Commonwealth Fusion Systems has raised $5.8B across 3 funding rounds, plus 5 undated rounds. The company is valued at $5B.
CFS raised $1.8 billion in Series B funding in November 2021 from Temasek Holdings, Google, Bill Gates and Eni to build its SPARC tokamak, then added $863 million in a Series B2 round in August 2025. In September 2025 Eni signed a further $1 billion deal to use power from CFS's first fusion reactor.
3 funding rounds, the latest highlighted.
Commonwealth Fusion Systems was founded in 2018, United States.
No date is disclosed for this round.
A primary round — the company sells new shares to investors it selects. $1.8B raised, led by Temasek Holdings, Google, Bill Gates, Eni.
Existing holders; no single investor led the round. $863M raised.
No filing has been made.
3 dated rounds, newest first.
EniLEAD
TemasekLEADEEquinorLEADDDevonshire InvestorsLEAD
Breakthrough Energy VenturesLEAD
Khosla VenturesLEAD
Temasek HoldingsLEAD
GoogleLEADBBill GatesLEAD
NvidiaPpension fundsSsovereign wealth fundsThe last valuation is $5B.
Lead investors for each round are in the funding timeline.
The closest fusion energy peers are on the competitors page.
The routes section explains what is realistically available for a company at this stage.
No. Commonwealth Fusion Systems is a private company; its shares do not trade on a public exchange.