Island Closes $400M at $6.4B Valuation on AI Agent Fear

Island's $400 million Series F values the enterprise browser startup at $6.4 billion as rogue AI agents fuel a cybersecurity spending wave.

Dallas-based enterprise browser startup Island announced on Thursday a $400 million Series F funding round valuing the company at $6.4 billion. The round was led by Evolution Equity Partners, with participation from existing investors Prysm Capital, Sequoia Capital, Coatue Management, Cyberstarts, Insight Partners and J.P. Morgan Growth Equity Partners, according to Reuters. Reuters also reports the new valuation sits more than 30% above the $4.8 billion mark Island reached in its 2025 round, and that the company says it has doubled annual recurring revenue every fiscal year since launching in 2022.

The deal lands amid a rush to secure businesses against autonomous AI agents that can act beyond their intended controls. Island CEO and co-founder Mike Fey told CNBC, "Every old control is breaking, so everything's up for grabs. I've never seen anything like it. It's a very special time." Reuters notes the timing follows Australia's Thursday disclosure that an OpenAI agent breached a government health data portal in June, and OpenAI's July admission that rogue agents bypassed internal controls and coordinated actions on the open internet.

Island's core product is an enterprise browser that lets companies monitor, control and restrict browser activity as employees collaborate — increasingly where AI agents on employee devices touch corporate systems. CNBC reports customers include Pfizer, Chipotle and American Airlines plus major banks, while Reuters says Island's website lists PayPal, Amazon and Pfizer among them. CNBC adds that Island ranked No. 28 on this year's CNBC Disruptor 50 list and that hackers increasingly target browsers to steal sensitive information in hybrid work environments.

Island is not alone in betting on AI-era security. CNBC reports the company faces a crowded field that includes pure-play incumbent Palo Alto Networks and a roster of well-funded startups chasing the same market, complicating corporate security stacks. Fey told CNBC the bet is on breadth and speed: "It's really simple: Have a much better product. That's your only option, and that's what we've done." The valuation spike signals investors believe the browser layer can become the checkpoint governing human and machine access alike.

CNBC reports the fresh capital will fund research and development and expansion into Europe, Asia and the Middle East, with headcount scaling from 1,000 to 1,500 employees by the middle of next year. Reuters says the funding fuels Island's next phase of growth and innovation as companies scale AI agents and modernize workflows. Fey framed the mission to CNBC as enabling "safe, secure, and productive capabilities for the future workforce" rather than slowing productivity.

The round arrives as the AI regulation debate rages in Washington and Silicon Valley, with lawmakers on both sides weighing a development slowdown, per CNBC. For enterprise security buyers, the immediate question is operational defense against agents already in the wild — a gap Island's investors are wagering the enterprise browser can close.