Private fusion funding thriving in 2025

1 October 2025

Through end September 2025, private fusion companies have raised $2.02 billion in equity and non-dilutive funding across 19 deals. Annualized, this suggests we might end the year at  $2.7 billion – a robust result that would leave 2025 as the second-best funding year in private fusion history, falling not far short of 2021’s $2.94 billion.

Commonwealth Fusion Systems $867 million Series B2 round accounts for 43% of the year-to-date total, underscoring both CFS’s dominant funding position but, even excluding this mega-round, the remaining ~$1.16 billion from 18 other deals would annualize to roughly $1.55 billion, exceeding every year except 2021 and still leaving 2025 a standout performance.

The sector has digested some $10 billion in cumulative funding through September 2025, with annual mean of the post-2021 period standing at $1.7 billion. Sustained capital commitment – particularly through 2022-2023’s broader venture downturn – signals solidifying investor conviction in fusion’s commercial timeline.