Cybersecurity firm Horizon3 has announced the completion of its Series E funding round, securing $250 million at a valuation exceeding $2 billion. This valuation represents a threefold increase from the $650 million recorded during its Series D round just over a year prior.
The oversubscribed round was co-led by existing investors NightDragon and NEA. The funding round also welcomed seven new investors: Acrew Capital, Blue Cloud Ventures, Demeter Group, Singapore’s EDBI, PSG, SAIC, and Sapphire Ventures. Five returning shareholders—Craft Ventures, Prosperity7 Ventures, Qualcomm Ventures, Ridge Ventures, and SignalFire—also participated. As part of this investment, Dave DeWalt, founder and CEO of NightDragon, who previously held leadership roles at FireEye and McAfee, and Morgan Kyauk, managing director at NightDragon, will join Horizon3’s board of directors.
The newly raised capital will be allocated across three primary areas. Horizon3 plans to expand its sales, marketing, and channel operations to better serve enterprise, mid-market, and federal clients. Concurrently, the company aims to enter new markets in Singapore and Australia while enhancing its presence across Europe, the Middle East, and Africa (EMEA). A significant portion of the investment will also accelerate product development, including the creation of autonomous blue-team agents capable of addressing issues identified by NodeZero pentests, thereby establishing a continuous learning feedback loop between offensive and defensive AI systems.
Horizon3’s flagship platform, NodeZero, is designed to autonomously and safely conduct penetration tests within a customer’s production environment. It identifies how adversaries could exploit chained misconfigurations, weak credentials, and identity gaps to compromise critical systems. The platform offers actionable remediation guidance, verifies implemented fixes instantaneously, and can deploy honeypots to detect AI-driven intrusions. This operational model has contributed to a 120% year-over-year growth in Annual Recurring Revenue (ARR) for the company. Horizon3 currently protects over 7,000 organizations globally, including multinational banks, healthcare networks, and four Fortune 10 firms.
The company holds FedRAMP High authorization and supports compliance with various regulatory frameworks, including DORA, NIS 2, NIST CSF 2.0, HIPAA, SOC 2, and GDPR. Horizon3 was recently recognized by the Deloitte Technology Fast 500 as the fastest-growing cybersecurity company in North America and was listed among Fast Company’s most innovative companies in 2026.
Snehal Antani, co-founder and CEO of Horizon3, commented on the funding, stating, “We invented the concept of AI Hackers and spent six years earning the right to autonomously pentest the most critical and sensitive networks in the world — with no humans in the loop. Our massive data moat – built on 310,000 tests safely executed in production – combined with thousands of radical champions who love our product, has allowed us to achieve consistent top-tier financial and operational metrics. This round gives us the fuel to scale aggressively as the definitive leader of the AI vs. AI era.”
Antani further explained the evolving challenges in cybersecurity, noting, “It has never been harder for CIOs and CISOs. Attackers are getting faster, enterprise IT is becoming more complex, and regulators and cyber insurers are becoming more punitive. We’re about to see an explosion of vulnerabilities, most of which won’t matter, but a small percentage will be immediately exploitable. The goal of running pentests isn’t to find problems, it’s to quickly fix exploitable problems that matter. We started with pentesting, evolved to be a proactive security platform, and will now accelerate remediation by creating AI learning loops between attackers and defenders.”
