Horizon3 Raises $250M Series E at $2B Valuation, Tripling Worth in 14 Months

San Francisco cybersecurity startup Horizon3 raised a $250 million Series E at a $2 billion valuation, more than tripling from $750 million-plus in 14 months. Returning investors NightDragon and NEA backed the round. The company, approaching $100 million ARR with 120% year-over-year growth, sells NodeZero, an autonomous penetration testing platform that has run 310,000 production tests with zero disruptions.