AI pentesting startup Horizon3 raises $250M at $2B valuation

Horizon3 raised a $250 million Series E at a $2 billion valuation. The company sells continuous, AI-powered security validation as an alternative to traditional annual penetration testing.

Why it matters: The raise reflects growing enterprise appetite for always-on automated security testing as AI both expands the attack surface and speeds up exploit discovery, a trend also visible in IBM's access-control findings and AI-assisted bug hunting at Chrome. It signals investors expect AI-driven security tooling to become a durable category rather than a one-off boom.