Cybersecurity startup Horizon3 has raised a $250 million Series E funding round at a $2 billion valuation, more than tripling its valuation in just 14 months. The round was led by returning investors NightDragon and NEA.

The funding comes as enterprises accelerate investments in cybersecurity amid the rise of AI-driven threats. Horizon3's NodeZero platform performs fully autonomous penetration testing, continuously scanning live production environments without disrupting operations, enabling organizations to identify vulnerabilities before attackers can exploit them.

The company said it has conducted more than 310,000 production security tests with zero operational disruptions, while approaching $100 million in annual recurring revenue (ARR) with 120% year-over-year growth.

With the new capital, Horizon3 plans to expand globally through new offices in Amsterdam, Australia, and Singapore, strengthen its partner ecosystem, and continue investing heavily in AI research and development. The company currently serves approximately 7,300 customers, ranging from managed service providers to Fortune 10 enterprises.