Horizon3 Raises $250M at $2B Valuation as AI Security Risks Intensify

Horizon3 raised a $250 million Series E at a $2 billion valuation, according to TechCrunch. The San Francisco-based cybersecurity startup drew backing from returning investors NightDragon and NEA. TechCrunch reports the valuation more than tripled in 14 months, signaling strong investor confidence in AI-powered security validation.

The funding comes as companies reassess how they test defenses against faster-moving AI-enabled threats. Horizon3’s pitch is built around continuous validation rather than relying on annual penetration tests. For security leaders, the practical takeaway is clear: periodic checks may no longer be enough when attack methods can evolve quickly.

Horizon3’s NodeZero platform is described as testing live systems without shutting down operations and scanning infrastructure continuously. TechCrunch reports the company says it has run 310,000 production security tests with zero disruptions. The company frames this as autonomous penetration testing, aimed at helping organizations understand whether their defenses are improving over time.

TechCrunch reports Horizon3 approached $100 million in annual recurring revenue last year with 120% year-over-year growth. The company has roughly 7,200 to 7,300 customers, spanning managed service providers serving small businesses through Fortune 10 enterprises. With new international offices and strategic investors including EDBI, SAIC, and Qualcomm, the round points to demand across multiple sectors, not just one cybersecurity niche.