Horizon3 hits $2 billion valuation with $250M Series E as AI threats escalate

Cybersecurity startup Horizon3 has raised a $250 cardinal Series E astatine a $2 cardinal valuation, much than tripling its valuation in 14 months. The San Francisco-based steadfast drew backing from returning investors NightDragon and NEA.

The backing arrives arsenic two large AI probe labs disclosed past week that their models had breached systems extracurricular their intended scope. Horizon3, which has spent six years gathering AI specifically designed to probe networks for vulnerabilities successful a controlled, authorized manner, is riding increasing endeavor demand. With AI-driven attacks accelerating, enterprises are rushing to stress-test their defenses astatine scale, a spread that accepted information vendors person mostly near unfilled.

Matt Hartley, the company’s main gross officer, said that its NodeZero level has 2 halfway strengths: It tin trial unrecorded systems without shutting down operations, a capableness different AI-powered tools person struggled to present reliably, and it scans an full infrastructure continuously alternatively than erstwhile a year, examining the afloat web alternatively than conscionable 2-3%.

The institution approached $100 cardinal successful yearly recurring gross past twelvemonth with 120% year-over-year growth,and expects to accelerate maturation this year, Hartley said.

AI tools person made it easier for attackers to make caller exploits quickly, forcing information teams to grip threats faster than they tin hole them. Horizon3 spent astir $100 cardinal successful R&D gathering automated systems designed to enactment predictable and controllable, Hartley said. That’s important fixed caller breaches astatine AI labs, which raised questions astir whether immoderate AI strategy tin genuinely stay contained.

“It’s besides making radical a batch much cautious astir however they deploy AI,” Hartley said. “We’re getting a batch of questions contiguous around: tin you observe AI? Of people we can. But I deliberation a batch of organizations that rushed to deploy AI crossed the endeavor are present reasoning doubly astir the ramifications of those deployments; what if my ain information squad gets excessively aggressive, could determination beryllium unintended consequences? So a batch of organizations are moving into what I’d telephone a bold caller world, which is precisely wherefore you request consistent, predictable investigating from a institution similar Horizon3, to cognize however to fortify your ain defenses against real-world exploits.”

In a statement, Horizon3 has tally 310,000 accumulation information tests with zero disruptions, establishing what it calls ‘AI Hackers’, afloat autonomous penetration testing.

The existent contention isn’t different bundle vendors; it’s the existing model, according to Hartley. Most companies prosecute quality information firms to tally yearly tests and those won’t disappear, helium continued. What’s shifting is what clients request aft signing up: Instead of sampling 5% of infrastructure erstwhile yearly, they present privation to scan everything monthly oregon weekly, tracking whether they’re really getting safer.

Horizon3’s founders, Snehal Antani and Anthony Pelletier, met portion serving astatine Joint Special Operations Command, wherever they saw firsthand however assets constraints made continuous information investigating difficult. They founded Horizon3 to automate those repetitive assessments.

With the funding, Horizon3 is expanding internationally,including caller offices successful Amsterdam (in June 2026), Australia, and Singapore, portion gathering a spouse web and maintaining important R&D spending.  

Strategic investors present see Singapore’s EDBI, defence contractor SAIC, and Qualcomm, signaling that the vulnerability they’re addressing extends good beyond immoderate azygous sector.

Horizon3 has astir 7,200 to 7,300 customers, ranging from managed work providers serving tiny businesses to Fortune 10 enterprises. The institution claims an addressable marketplace of tens of billions of dollars, a fig that aligns with manufacture estimates of the broader cybersecurity market, valued astatine $271.9 cardinal successful 2025 and projected to scope $663.2 cardinal by 2033, according to Grand View Research.