Written by Admin Alex · Fact-Checked by M.Ali · Info Verified September 2026
We review and update this article regularly as new information becomes available.
TL;DR: Island just raised $400 million at a $6.4 billion valuation to keep building its Enterprise Browser, the product it uses to control what both employees and AI agents are allowed to do inside company systems.
$400 million. That is what Island just added to its balance sheet in a Series F round that pushes the company’s valuation to $6.4 billion. That figure is more than double where Island stood back in 2024, and it lands at a moment when enterprise security money is chasing one question above all others: who gets to say what an AI agent is allowed to touch.
Evolution Equity Partners led the round. The rest of the investor list reads like a roll call of firms that have been circling cybersecurity all year: Prysm Capital, Sequoia Capital, Coatue Management, Cyberstarts, Insight Partners, J.P. Morgan Growth Equity Partners, Alta Park Capital, Georgian, G Squared, and Squarepoint all wrote checks. Dmitri Alperovitch, the Crowdstrike co-founder who has become one of the more recognizable names in the security world, put in a personal investment as well. That kind of name attached to a term sheet tends to turn heads even before the valuation number does.
Island launched in 2022, so this is a four-year-old company we are talking about, not a decade-old incumbent. It employs roughly 1,000 people today. What has kept investors circling back is the growth line: annual recurring revenue has doubled every fiscal year since the company opened its doors. A curve like that is what turns a $6.4 billion valuation from a bold bet into something closer to arithmetic.
What Island Is Actually Selling
The pitch starts with the browser. Island calls its product an agentic control plane, built around what it markets as the Enterprise Browser. The logic is simple enough: nearly all corporate work already happens inside a browser tab, so instead of bolting security onto a pile of separate endpoints and applications, Island puts the control layer directly where the work is done. From that vantage point it governs human employees and AI agents side by side, giving security teams visibility into activity, access controls over who or what can reach which data, data protection rules, and audit trails that run across browsers, endpoints, networks, and applications.
The AI agent piece is probably the real reason this round landed at this size. Boards are approving AI agent rollouts faster than most security teams can figure out how to supervise them, and that gap is exactly where Island is trying to plant its flag. The platform is built so organizations can put AI agents to work without losing the ability to define what those agents can and cannot do. That covers identity governance, so an agent operates with a defined identity rather than a blank check, plus access management, guardrails, data boundaries, approval workflows for anything sensitive, and audit trails detailed enough to reconstruct exactly what an agent did and when it did it.
“Those combined capabilities give CIOs, CISOs, and business unit owners one security, productivity, and governance framework,” said Mike Fey, Island’s CEO.
CTO Dan Amiga describes the architecture as a stack rather than a single feature. “Island’s control plane unifies five critical layers: last-mile control, network, data, identity, and observability,” he said, laying out the pieces that have to hold together for any of this to survive contact with a real enterprise security review.
Why This Round Is a Signal, Not Just a Number
None of this is happening in a vacuum. Security budgets have spent this year chasing AI adoption, and investors are treating agent governance less like a nice-to-have bolted onto existing tools and more like infrastructure companies will need no matter which AI vendor they end up standing behind. A $400 million check anchored by Evolution Equity Partners, with Sequoia and Insight Partners both in the mix, is not the kind of bet firms make on a feature. It is the kind of bet firms make when they think a category is about to become mandatory spend.
That said, $6.4 billion is a lot of confidence to place on a bet that enterprises will keep needing a dedicated layer just to keep AI agents in check rather than folding that job into tools they already own. Island still has to prove that browser-centric control stays the right answer as agents start operating outside the browser entirely, in APIs and backend systems where a browser-based product has less natural reach.
Related: Island’s raise lands the same week Amazon opened its seller backend to Anthropic’s Claude, and it’s not the only company leaning on Claude. See how Anthropic says Claude now leads a quarter of its own R&D.
Bottom Line: Investors are not just betting on Island, they are betting that the entire idea of “who gets to let an AI agent touch what” becomes one of the biggest line items in enterprise security spending, and right now that bet looks like it is paying off.
