Island Raises $400 Million Series F at $6.4 Billion Valuation to Secure AI Agents

Island, a Dallas-based cybersecurity company known for its enterprise browser and an emerging agentic control plane, announced on September 24, 2026 that it has raised $400 million in a Series F funding round. The round values the company at $6.4 billion, a figure that more than doubles its valuation since 2024. The funding was led by Evolution Equity Partners, with participation from a long list of existing and new investors. The announcement underscores intense investor interest in security tools that govern AI agents inside large organizations.

The company, founded by CEO Mike Fey and CTO Dan Amiga, emerged from stealth in 2022 with a browser built to put security, IT controls and productivity tools directly into the software employees use every day. Since then, Island has expanded into data protection, data loss prevention (DLP) and a next-generation SASE architecture that works from the endpoint outward. Its latest product, an agentic control plane, aims to give enterprises visibility, control and auditing over what both employees and AI agents do across endpoints, networks and data.

The raise comes amid a broader scramble to secure businesses against rogue or misbehaving AI agents. That theme has drawn widespread attention in 2026, particularly after OpenAI's agent-orchestrated attack on Hugging Face. As companies rush to deploy AI agents that can interact with applications, data and corporate systems with increasing independence, traditional security controls are struggling to keep up. Island's pitch is that it can see and govern what people and agents are doing as they interact with applications and data, wherever that happens.

Island's path to this point has been steady. The company raised $175 million in 2024 at a $3 billion valuation, then $250 million in March 2025 at a $4.8 billion valuation. The new Series F brings total investment in Island to well over $1 billion, according to SecurityWeek. Island employs 1,000 people and has doubled annual recurring revenue (ARR) every fiscal year since its 2022 launch.

Key Facts

Reuters reported on September 24, 2026 that Island raised $400 million in a funding round that valued it at $6.4 billion. The latest funding values Island at more than 30% above its $4.8 billion valuation in a 2025 funding round, although the company's own release says the valuation has more than doubled since its $3 billion 2024 round.

The Series F 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. Additional participants included Alta Park Capital, Georgian, G Squared and Squarepoint, alongside another personal investment from cybersecurity entrepreneur Dmitri Alperovitch, the former CrowdStrike CTO. Richard Seewald, Founder and Managing Partner at Evolution Equity Partners, said that Island meets the moment with a unique advantage: it can see and govern what people and agents are doing.

Island's platform includes an enterprise browser and an agentic control plane. The company says the platform provides zero trust network access (ZTNA), device posture assessment, and inline data loss prevention without traditional VPNs. Security teams can implement granular DLP rules directly where work occurs, blocking unapproved clipboard transfers, downloads, and screen captures.

CNBC reported on September 24, 2026 that Island plans to invest in research and development and power its expansion into new markets, including Europe, Asia and the Middle East. CEO Mike Fey told CNBC in an exclusive interview that the company plans to scale its workforce from 1,000 to 1,500 employees by the middle of next year. Fey also said, "Every old control is breaking, so everything's up for grabs. I've never seen anything like it. It's a very special time."

Calcalist reported on September 24, 2026 that Island had reached approximately $200 million in revenue and was growing at about 100% annually. The company said eight of the world's 10 largest banks were using its enterprise browser. Island counts Pfizer, Chipotle, American Airlines and major banks among its customers. It ranked No. 28 on this year's CNBC Disruptor 50 list. The company was also named a Customers' Choice in the 2026 Gartner Peer Insights Voice of the Customer for Secure Enterprise Browsers and recognized by Frost & Sullivan as the 2026 Global Zero Trust Browser Security Company of the Year.

Analysis

The bigger picture here is that Island's raise is a direct bet on a new category of security software: governance for AI agents. As enterprises deploy agents that can act independently across systems, the old boundaries between endpoint, network and data security are dissolving. Island's CEO Mike Fey captured the moment when he told CNBC that every old control is breaking. That is why investors are willing to pay a premium for a platform that claims to govern both human and machine activity from a single control plane.

The competitive landscape is crowded. Pure-play incumbents such as Palo Alto Networks are pushing into adjacent areas, and a roster of startups is racing to win a slice of the ballooning AI security market. Fey's response to that pressure is blunt: "It's really simple: Have a much better product." Island's differentiation rests on its enterprise browser, which it created as a new category, and its expansion into an endpoint-outward SASE architecture. As CTO Dan Amiga said, agents do not operate in a single layer of the technology stack, so they cannot be governed from one.

What this really means is that the market is rewarding security vendors that can address the agentic era with a unified platform rather than a patchwork of point solutions. Island's ability to double ARR every fiscal year since 2022, reach roughly $200 million in revenue, and grow at about 100% annually shows that demand is real. That kind of validation is hard to fake, and it explains why Evolution Equity Partners led the round and why existing investors like Sequoia Capital, Coatue Management and Insight Partners followed on.

At the same time, the regulatory environment is unsettled. The battle over AI regulation is raging in Washington and Silicon Valley, and lawmakers on both sides of the aisle are debating a development slowdown. That uncertainty could cut both ways: stricter rules might force enterprises to invest more in governance and auditing tools, which would benefit Island, or they could slow down AI agent adoption altogether. Island's expansion into Europe, Asia and the Middle East also exposes it to a patchwork of data protection regimes, which its platform is partly designed to address.

Why It Matters

Island's funding round matters because it shows how quickly the security industry is reorganizing around AI agents. Just a few years ago, the enterprise browser was a novel idea. Now, the same company is positioning itself as a control layer for a workforce that includes both people and autonomous software. If that vision holds, the way companies buy security will change: instead of stitching together separate tools for endpoints, networks and data, they may look for a single platform that can see and govern every interaction, whether it is initiated by a human or an agent.

The round also matters for the broader startup ecosystem. A $6.4 billion valuation for a company that was valued at $3 billion in 2024 and $4.8 billion in March 2025 signals that investors are still willing to pay up for cybersecurity assets with strong revenue growth and a clear story around AI risk. SecurityWeek reported on September 24, 2026 that the latest funding brings total investment in Island to well over $1 billion. That kind of capital gives Island room to invest in research and development and to expand into new markets, including Europe, Asia and the Middle East.

Finally, the raise matters because it highlights the gap between AI adoption and AI governance. Enterprises are deploying agents faster than they can secure them. Island's pitch is that it can close that gap by providing context, access, guardrails and accountability for agents, just as it does for humans. Whether or not Island wins the category, the problem it addresses is now on every chief information security officer's agenda.

Next Up

Island plans to use the new funding to enhance its platform and boost growth. The company will invest in research and development and power its expansion into Europe, Asia and the Middle East. It also intends to scale its workforce from 1,000 to 1,500 employees by the middle of 2027. With total investment now well over $1 billion and a valuation that has more than doubled since 2024, Island has the resources to push deeper into the agentic control plane market.

The coming months will test whether Island can maintain its growth rate while fending off competition from pure-play incumbents like Palo Alto Networks and a growing list of startups. The company's next moves in product development and international expansion will be closely watched by investors and security teams alike. For now, the Series F stands as one of the clearest signals yet that AI agent security has become a central concern for the enterprise.