Onyx Security Raises $113M to Guard AI Agent Security

A New Wave of AI Security Funding

Onyx Security, an Israeli cybersecurity startup, has raised $113 million to address the escalating risks posed by autonomous AI agents operating inside enterprise environments 1. The round underscores a broader shift in venture capital: as companies race to deploy AI agents that can act independently across business systems, investors are pouring money into startups built specifically to monitor, govern, and secure them.

Onyx's raise is not an isolated bet. Zenity, another startup focused on policing AI agents, recently closed a $125 million round backed by SoftBank, Hitachi, and LG 7. Zenity's CEO Ben Kliger described the urgency driving this investment, noting that AI agents are increasingly touching “every aspect of the enterprise,” a dynamic especially pronounced among Asian companies rushing to integrate agentic AI into their operations 7. Together, the Onyx and Zenity rounds signal that AI agent security has become one of the most actively funded niches within cybersecurity, as enterprises grapple with the reality that autonomous systems making decisions and taking actions on their own introduce new categories of risk that traditional security tools were never built to handle.

Cybersecurity's Broader Investment Boom

The enthusiasm for AI-agent security fits into a larger pattern of surging valuations across cybersecurity. Horizon3, a cybersecurity firm, raised $250 million in a round that more than tripled its valuation to over $2 billion within roughly a year, reflecting how investors are rewarding companies addressing growing enterprise demand for protection amid rapid AI adoption 3. While Horizon3's focus differs from the agent-specific security niche occupied by Onyx and Zenity, its trajectory illustrates the scale of capital now flowing into the sector as a whole.

AI Investment Beyond Security

The funding surge extends well beyond cybersecurity. Infrastructure providers are also cashing in: optical networking company Lumilens reached a $5.51 billion valuation in its latest round, driven by surging investment in AI data centers and the resulting demand for high-speed connectivity 6. Elsewhere, startups are finding niches adjacent to AI's commercial applications — Gravity, which places advertisements inside AI platforms like ChatGPT, raised $30.5 million and is already exploring agent-to-agent advertising 2, while a team of ex-Spotify employees raised $10 million to bring recommendation-engine AI into e-commerce 5.

A Note of Caution

Not all the coverage is uniformly optimistic. One report highlights that corporate finance chiefs are cutting jobs and freezing hiring to redirect budgets toward AI initiatives, yet many of these investments are failing to deliver the returns executives expected 4. That tension — heavy capital commitment against uncertain payoff — frames the current funding boom. Investors are betting big on both AI capability and AI safety infrastructure, but whether that spending translates into durable enterprise value remains an open question even as valuations climb across the sector.