Island’s $6.4B Valuation Validates a Different Kind of Agent Security – And It Starts in the Browser

Island, the enterprise browser company, has secured $400 million in Series F funding at a $6.4 billion valuation, marking a major milestone in the development of the "agentic control plane." The round, led by Evolution Equity Partners with participation from Sequoia, Coatue, Cyberstarts, Insight, J.P. Morgan, Prysm, Alta Park, Georgian, G Squared, and Squarepoint, brings the company's total funding to over $900 million. Dmitri Alperovitch, co-founder of CrowdStrike, also joined as an investor. The valuation represents a 33% step-up from the company's $4.8 billion Series E round in March 2025. Island's annual recurring revenue (ARR) has reportedly doubled every fiscal year since its launch in 2022, though exact figures were not disclosed.