Island and Cyera lead week’s largest funding rounds with $400m each

Cybersecurity unicorns Island and Cyera each raised $400m this week, topping Crunchbase’s list of the ten largest US venture rounds for the period of 19 to 25 September 2026.

Dallas-based Island, which builds tools for secure enterprise digital operations, closed a Series F led by Evolution Equity Partners at a $6.4bn valuation, more than double its 2024 figure. New York-based Cyera, which provides enterprise data security tools governing both humans and AI agents, took a $400m Series G extension led by Evolution Equity Partners with Goldman Sachs Growth Equity participating, bringing its total funding to $2.7bn.

The rest of the top ten spanned foundational AI, drug discovery, neurotech, wireless communications, pharmacy benefits, cloud seeding, tax compliance and AI training data.