Key Takeaways
- Onyx Security raised $113 million in a Series B round led by Bessemer Venture Partners, valuing the company at roughly $640 million just four months after exiting stealth.
- The startup’s platform provides enterprises with permission management, activity monitoring, and risk prevention for AI agents, aiming to become the control layer for large‑scale AI adoption.
- Founded in 2024 by former Unit 8200 veteran Maxim Bar Kogan and AI entrepreneur Gil Elbaz, Onyx now employs over 80 people across Israel, the U.S., and Canada and counts several Fortune 500 firms among its early customers.
- Anthropic has already integrated Onyx’s technology to help its enterprise clients deploy AI securely, validating the startup’s approach.
- The founders stress that rapid post‑stealth demand exceeded expectations, prompting an accelerated financing round and reinforcing investor confidence in AI security as a high‑growth cybersecurity category.
- Onyx plans to use the new capital to advance its AI‑model development, expand sales, business‑development, and marketing teams domestically and internationally, and solidify its position as a category leader.
Funding Round Details and Valuation
Onyx Security announced a $113 million Series B financing round led by Bessemer Venture Partners, with participation from existing investors and new strategic backers. The infusion brings the company’s total capital raised to approximately $188 million, comprising a $5 million seed round, a $35 million Series A, and the earlier $40 million stealth‑stage round. Post‑money valuation is estimated at around $640 million, marking a several‑fold increase from the valuation implied by its Series A. The speed of the raise—just four months after emerging from stealth—underscores strong market appetite for solutions that address the security challenges posed by autonomous AI systems.
Company Background and Founding Team
Founded in 2024, Onyx Security brings together deep expertise in elite military units and AI product leadership. Co‑founder and CEO Maxim Bar Kogan served in Israel’s Unit 8200 and later held the role of Vice President of Product and Engineering at Mixtiles, where he drove enterprise‑focused AI initiatives. Co‑founder Gil Elbaz is an AI entrepreneur with a background in the Israeli Air Force’s Operational Technology Unit, giving him insight into the operational risks of deploying intelligent systems in high‑stakes environments. Their combined experience has shaped Onyx’s focus on building a robust security layer that can govern AI agents across diverse enterprise contexts.
Platform Capabilities and Technology
Onyx’s core offering is a platform designed to enable enterprises to discover, manage, and govern AI agents—whether developed in‑house or sourced from third‑party providers—throughout their entire lifecycle. The technology continuously monitors each stage of an agent’s reasoning process, capturing inputs, decision points, and outputs to detect anomalous or malicious behavior. By enforcing fine‑grained permissions and providing real‑time alerts, the platform allows organizations to prevent unintended actions before they cause damage, remediate issues swiftly, and maintain compliance with internal policies and external regulations. This end‑to‑end oversight addresses a critical gap left by traditional cybersecurity tools, which were not built for the fluid, autonomous nature of AI agents.
Stealth Emergence and Early Traction
Onyx exited stealth mode earlier this year after securing an initial $40 million round that enabled the company to begin broad sales efforts. According to Maxim Bar Kogan, the transition from stealth marked the point at which the startup could start selling its solution at scale. Demand quickly surpassed internal forecasts, allowing the company to hit its revenue targets ahead of schedule and generating significant investor enthusiasm. This rapid adoption signaled a clear market need for dedicated AI‑agent security controls and set the stage for the accelerated Series B round just months later.
Strategic Integration with Anthropic and Customer Base
A notable early validation came in June when AI safety research firm Anthropic announced the integration of Onyx’s technology into its enterprise offerings. The partnership allows Anthropic’s customers to leverage Onyx’s permissioning and monitoring capabilities to deploy large‑language models and other AI agents safely within corporate environments. Beyond Anthropic, Onyx reports working with several Fortune 500 companies across finance, healthcare, and manufacturing sectors, indicating that its solution resonates with enterprises that require stringent oversight of AI‑driven workflows.
CEO Perspective on Growth and Investor Confidence
Speaking to Calcalist, Maxim Bar Kogan emphasized that the size of the financing reflects investors’ conviction that AI security will become one of the most important markets within cybersecurity. He noted that the funding round was raised sooner than anticipated because the company’s post‑stealth performance demonstrated a product‑market fit that exceeded expectations. Bar Kogan framed Onyx’s ambition not as a quick‑sale target but as the creation of an independent, global leader in AI agent governance, buoyed by strong momentum and a clear vision for controlling the proliferation of autonomous AI systems.
Vision for the AI Security Market
Bar Kogan articulated a broader thesis: the rise of artificial intelligence is reshuffling competitive dynamics across industries, leaving incumbents vulnerable and opening opportunities for agile startups to redefine markets. He argued that trillions of dollars flowing into AI investments will generate billions in value for companies that can ensure those AI systems are deployed safely and compliantly. According to him, very few vendors today provide comprehensive control over AI agents, positioning Onyx to capture a substantial share of an emerging category that could become a cornerstone of enterprise cybersecurity strategies in the coming decade.
Investor Perspective and Future Plans
Hila Zigman, General Partner at Cyberstarts—which led Onyx’s Seed round—highlighted the significance of the startup’s work in defining a new cybersecurity niche. She explained that as AI agents become integral to critical enterprise workflows, organizations need assurance that these systems operate securely, consistently, and in accordance with corporate policies. Onyx’s technology builds the control layer necessary for large‑scale AI adoption, a capability she believes will rank among the most vital cybersecurity areas over the next ten years. The freshly raised capital will be allocated to accelerating the development of next‑generation AI models, expanding the sales, business‑development, and marketing teams in the United States and other international markets, and continuing to fortify partnerships with major technology providers and enterprise clients.
Broader Industry Impact and Conclusion
Onyx Security’s rapid fundraising and technological advancements illustrate a shifting landscape where AI‑centric security solutions are no longer speculative but essential. By addressing the unique risks posed by autonomous AI agents—such as unintended behavior, permission sprawl, and opaque decision‑making—the company offers a pragmatic pathway for enterprises to harness AI’s productivity gains without compromising safety or compliance. As more organizations embed AI into core operations, the demand for platforms like Onyx’s is expected to grow exponentially, potentially catalyzing a new wave of cybersecurity innovation focused specifically on AI governance. With robust backing, a seasoned founding team, and early traction among Fortune 500 firms, Onyx appears well positioned to become a defining player in this emergent market.