Cybersecurity firm Island has secured $400 million in a Series F funding round, bringing its total valuation to $6.4 billion. The investment was led by Evolution Equity Partners, with participation from existing investors Sequoia Capital and Prysm Capital.
The company plans to use the new capital to expand its core platform, specifically focusing on security solutions for AI agents within enterprise environments. Island provides an enterprise browser that integrates security and IT controls to manage data and identity for both human and AI users.
Founded in 2020, Island has seen rapid growth, with its valuation more than doubling in less than two years. As of September 2026, the company reported approximately $200 million in annual recurring revenue, marking a 100% year-over-year increase.
Headquartered in Dallas with operations in Israel, Island currently employs around 1,000 people. Its client base exceeds 700 enterprise customers, including eight of the ten largest global banks, as well as companies such as Citi, Pfizer, and T-Mobile.
