Horizon3 has raised a $250 million Series E at a $2 billion valuation, a round co-led by returning investors NightDragon and NEA.
The funding, reported by TechCrunch, comes as enterprises accelerate efforts to validate defences after two AI research labs disclosed models had breached systems, and it backs Horizon3’s effort to commercialise continuous, authorised attack simulation via its NodeZero platform that can test live systems without shutting down operations and scan an entire infrastructure continuously rather than sampling a small percentage.
"Can you detect AI? Of course we can," Horizon3 chief revenue officer Matt Hartley said, describing demand from organisations that rushed AI deployments and now want predictable, frequent testing.
The company said it approached $100 million in annual recurring revenue last year with 120% year-over-year growth, has run roughly 310,000 production security tests with zero disruptions, and serves about 7,200 to 7,300 customers.
The new round includes strategic participants such as EDBI, SAIC, and Qualcomm, pairing commercial scale investors with defence- and government-aligned backers as Horizon3 pushes into federal and enterprise accounts.
The raise follows a roughly $100 million Series D about a year earlier and more than triples the company’s valuation in just over a year, and Horizon3 says proceeds will fund international expansion, new offices and partner channels while sustaining substantial R&D spending to automate and scale its autonomous pentesting product.
