AI startup Island has closed a $400 million Series F funding round led by Evolution Equity Partners, reaching a $6.4 billion valuation. Existing investors Prysm Capital, Sequoia Capital, Coatue Management, Cyberstarts, Insight Partners, and JP Morgan Growth Equity Partners also participated in the round. The capital will support Island's next phase of growth as it helps enterprises scale AI agent deployment and modernize workplace operations. The funding aims to accelerate innovation in enterprise AI infrastructure and expand the company's market reach.