Two $400M rounds in one week: capital flows into security for AI agents

Crunchbase News' weekly roundup of U.S. rounds for Sept. 19-25, 2026 shows the two largest deals both in cybersecurity, each at $400 million. Island, the Dallas-based developer of a control layer for enterprise digital operations, raised a $400 million Series F led by Evolution Equity Partners at a $6.4 billion valuation, more than double its 2024 mark. Cyera, the New York data-security company, took another $400 million as a Series G extension from Growth Equity at Goldman Sachs Alternatives, after a $600 million Series G in June 2026 led by Evolution Equity.

Both deals target the same problem: controlling AI agents inside enterprises. Island says it reached roughly $200 million in revenue by September 2026, growing about 100% annually, with 1,000 employees versus more than 500 a year earlier, and eight of the world's 10 largest banks using its enterprise browser; it has raised more than $1 billion since launching in 2020. Cyera governs access for both humans and non-human accounts, and in early September 2026 acquired Oasis Security, a non-human identity specialist, for $1 billion in cash and stock. Crunchbase data puts Cyera's total funding at $2.7 billion.

For Vietnamese angel investors, the usable lesson is not the Series F or G itself — that is growth-fund territory. It sits in three places: (1) agent access governance is being priced richly, and Vietnamese banks, brokerages and telcos are deploying AI assistants now, so teams building the deployment, logging and compliance layer for them have paying domestic customers; (2) the realistic exit for such startups is a sale to a larger platform — the $1 billion Oasis Security deal is the example — so angel checks should be underwritten for M&A, not listing; (3) local seed pricing should be anchored to the regional benchmark: the median Southeast Asian Series A in H1 2026 was $8 million, so an overpriced first round pushes the company toward a down round when it raises regionally.