Fusion Startups Hit Funding Wall After Raising Record Billions

Commonwealth Fusion Systems, which raised $1.8 billion in 2021, has postponed its next funding round indefinitely. TAE Technologies cut 15% of staff after missing a $500 million Series G target. The slowdown reflects venture capital's recalibrated risk appetite for deep tech: unlike software, fusion projects demand sustained capital over decade-plus timelines, making them acutely sensitive to investor appetite shifts. The correction mirrors patterns from the cleantech boom of the late 2000s, where speculative enthusiasm gave way to evidence-based evaluation.