Cybersecurity startup Horizon3 has completed a $250 million Series E funding round, bringing its valuation to $2 billion. This represents more than a tripling of its valuation over the past 14 months.
The San Francisco-based firm received investment from returning backers NightDragon and NEA. The funding coincides with recent disclosures from two major AI research labs regarding their models breaching systems outside their intended scope.
Horizon3 has developed AI specifically to probe networks for vulnerabilities in a controlled and authorised manner over six years. Matt Hartley, the company's chief revenue officer, stated that its NodeZero platform can test live systems without operational shutdowns and continuously scans entire infrastructures.
The company approached $100 million in annual recurring revenue last year, experiencing 120% year-over-year growth. Horizon3 expects to accelerate this growth during the current year.
Horizon3 has conducted 310,000 production security tests without disruptions, utilising what it terms 'AI Hackers' for fully autonomous penetration testing. The company's founders, Snehal Antani and Anthony Pelletier, met at Joint Special Operations Command and founded Horizon3 to automate repetitive security assessments.
With the new funding, Horizon3 is expanding internationally, including opening new offices in Amsterdam in June 2026, Australia, and Singapore. The company also plans to build a partner network and maintain significant research and development spending.