Agentic Control Plane Maker Island Raises $400M Series F at $6.4B Valuation

The enterprise browser market is consolidating fast. Palo Alto Networks acquired Talon Cyber Security for $458.6 million in late 2023 to fold into its Prisma SASE service, and this year both CrowdStrike (Seraphic Security) and Akamai (LayerX Security, for roughly $205 million) snapped up rivals. While competitors get absorbed into bigger security platforms, Island is doing the opposite — growing bigger on its own.

Founded in 2020 and out of stealth since 2022, the Dallas-based company created the “Enterprise Browser” category by embedding security, access control, and productivity tools directly into the browser employees already use. It has since expanded into a consumer browser extension, endpoints, next-generation SASE architecture, and data protection, and now positions itself as an “agentic control plane” governing both people and AI agents. The pitch: one policy engine and one audit trail across five layers — last-mile control, network, data, identity, and observability — showing in real time who or what is acting, what it can reach, and whether that action should be allowed. Eight of the world’s ten largest banks now use Island’s Enterprise Browser, and headcount has doubled to 1,000 from over 500 a year ago. CTech reported Island’s revenue reached roughly $200 million by September 2026, growing near 100% annually.

Island was co-founded in 2020 by Mike Fey and Dan Amiga. CEO Fey previously served as EVP of enterprise products at McAfee and CTO of Intel Security after Intel’s acquisition of McAfee, then as President and COO of Blue Coat Systems, where he led the deal that sold Blue Coat to Symantec for $4.7 billion. CTO Amiga invented web isolation technology as founder of Fireglass, which he sold to Symantec for $250 million in 2017 — the deal that first connected him with Fey. Before that, he headed software security at Microsoft’s Technology Center in Tel Aviv and served in Israel’s Unit 8200 cyber intelligence corps.

Island has closed a $400 million Series F led by Evolution Equity Partners, with participation from existing investors Prysm Capital, Sequoia Capital, Coatue Management, Cyberstarts, Insight Partners, J.P. Morgan Growth Equity Partners, Alta Park Capital, Georgian, G Squared, and Squarepoint, alongside a personal investment from cybersecurity entrepreneur and CrowdStrike co-founder Dmitri Alperovitch. The round values Island at $6.4 billion, more than double the $3 billion valuation it carried after its $175 million Series D in 2024. Island had raised $250 million at a $4.8 billion valuation in its Series E last March.

CEO Mike Fey said people and AI agents are now working side by side, and that agents need the same context, access, guardrails, and accountability that humans do to succeed — capabilities Island has built by extending from the browser into data protection and SASE architecture, giving CIOs, CISOs, and business units one framework to govern both. Evolution Equity Partners founder Richard Seewald said Island has already shown it can create a category, displace legacy technology, and accelerate customer transformation from the browser to the network, calling it the control layer for the next generation of enterprise computing. Cyberstarts founder Gili Raanan, an investor since Island’s early days, said doubling ARR every year on the way to a $6.4 billion valuation is clear evidence the company built something enterprises genuinely need.

Island was named to the CNBC Disruptor 50 list for 2026, recognized by Frost & Sullivan as its 2026 Global Zero Trust Browser Security Company of the Year, and named a Customers’ Choice in Gartner Peer Insights’ Voice of the Customer for Secure Enterprise Browsers.

The Competition

The enterprise browser market has been reshaped by acquisitions over the past year. Palo Alto Networks acquired Talon Cyber Security for $458.6 million in December 2023, folding its enterprise browser into Prisma SASE to secure access from unmanaged devices.

Menlo Security takes a different approach, using cloud-based remote browser isolation (RBI) to protect any browser rather than building its own. It raised a $100 million Series E led by Vista Equity Partners at an $800 million valuation.

LayerX Security, which secures browsers through a lightweight extension rather than a full replacement, agreed to be acquired by Akamai for roughly $205 million this May. Seraphic Security was acquired by CrowdStrike earlier this year to fold browser telemetry into its Falcon platform.

With three rivals absorbed into larger platforms, Island remains the largest independent player in the category — and just got bigger.