Island Raises $400 Million at a $6.4 Billion Valuation for Browser Security

Island has raised $400 million in a Series F round that values the Dallas-based security company at $6.4 billion. The financing gives its enterprise browser business room to grow as companies consider how to defend against risks from AI agents.

Capital for research and new markets

Evolution Equity Partners led the round. Existing investors Prysm Capital, Sequoia Capital, Coatue Management, Cyberstarts, Insight Partners and J.P. Morgan Growth Equity Partners also participated. It is a sizable investment in Island’s effort to sell security controls through the browser employees use for work.

Island plans to invest in research and development and expand into Europe, Asia and the Middle East. CEO Mike Fey told CNBC he also plans to grow the workforce from 1,000 to 1,500 by mid-2027. The hiring target is a plan announced alongside the financing, not a specified allocation of the proceeds.

Why the browser is Island’s starting point

Island’s enterprise browser lets businesses monitor and control browser activity as employees collaborate. Browsers are targets for attackers seeking sensitive information, particularly in hybrid work environments. Island puts its controls at that point of activity, where employees work and access information.

CNBC frames the round against growing interest in tools to defend businesses from rogue AI agents. Fey sees established security controls coming under pressure. That is his view of the market; Island’s browser is one proposed way for businesses to manage security as their work changes.

The test beyond the funding round

Island faces established security companies, including Palo Alto Networks, as well as startups pursuing AI-security customers. Fey is betting that a broad platform will appeal to businesses seeking greater productivity and fewer tools. The pitch asks buyers to see a browser as part of a simpler security setup, rather than another product to manage.

Island counts Pfizer, Chipotle, American Airlines and major banks among its customers. That gives it an existing business to build on as it enters new markets. The commercial question is whether its browser-led approach can win more customers in a crowded field, especially as those customers assess new risks from AI agents.