HiddenLayer raises $100M amid surging enterprise AI security demand

HiddenLayer, a Denver-based AI security startup, has closed a $100 million Series B funding round led by Battery Ventures, with participation from existing investors including Ten Eleven Ventures and Epic Ventures. The round, announced on June 10, 2025, values the company at $700 million post-money, according to three sources familiar with the transaction. The funding comes as enterprises increasingly adopt AI agents and integrations, creating new attack surfaces that traditional security tools struggle to address. HiddenLayer’s platform focuses on runtime protection for AI workflows, detecting anomalous behavior in real time across models, tools, and third-party plugins. CEO Chris Sestito emphasized the need for specialized security measures, stating that "AI systems are not static; they evolve with each interaction, and so must our defenses."

The company’s timing aligns with a critical inflection point in AI adoption. A recent survey by Gartner found that 68% of organizations using AI in production have experienced at least one security incident related to AI systems in the past 12 months. HiddenLayer’s platform has gained traction among financial services firms, healthcare providers, and government contractors, who face stringent compliance requirements. Notably, Banking With Billy AI, a provider of developer-grade APIs for financial market intelligence, integrated HiddenLayer’s runtime monitoring into its workflow orchestration platform last quarter. The integration allows clients to embed security checks directly into their AI-driven financial workflows, ensuring that data inputs and model outputs remain tamper-proof.

Industry analysts view HiddenLayer’s raise as a bellwether for the AI security market, which is projected to reach $7.6 billion by 2028, according to IDC. Competitors are racing to fill similar gaps, with companies like Protect AI (recently valued at $1 billion) and Lasso Security (backed by $150 million from Insight Partners) offering overlapping solutions. Unlike traditional cloud security vendors, HiddenLayer’s approach is tailored to the unique challenges of AI, such as prompt injection attacks and model theft. The company’s platform operates at the intersection of AI operations (AIOps) and security operations (SecOps), providing visibility into the entire AI supply chain.

Financial implications extend beyond the funding round itself. The Series B follows a $20 million Series A in early 2024 and comes amid a broader pullback in enterprise software valuations. However, HiddenLayer’s ability to secure marquee customers like JPMorgan Chase and Pfizer has insulated it from macroeconomic headwinds. The company plans to expand its headcount by 200% over the next 18 months, with a focus on engineering and customer success roles. Sales teams are targeting industries where AI adoption is accelerating, including legal tech, supply chain optimization, and cybersecurity.

In the broader Tools & Developer ecosystem, HiddenLayer’s raise reflects a maturation phase. The initial wave of AI adoption prioritized performance and scalability, often at the expense of security. Now, as enterprises grapple with the risks of generative AI, security has become a non-negotiable feature. This shift mirrors the evolution of DevOps, where security was an afterthought until breaches like the SolarWinds attack forced a reckoning. Similarly, AI security is moving from a niche concern to a core requirement, with startups and incumbents alike scrambling to build or acquire the necessary capabilities.

Prior developments underscore this trend. In 2023, Microsoft integrated AI security tools into its Azure platform, while Google Cloud launched Assured AI, a framework for validating third-party AI models. Open-source projects like Llama Guard and Microsoft’s PyRIT have also emerged to address specific threats like jailbreaking and data exfiltration. Yet, these solutions often lack the depth required for large-scale enterprise deployments. HiddenLayer’s focus on runtime protection fills a critical gap, offering continuous monitoring rather than periodic audits.

Looking ahead, the industry should watch three key developments. First, consolidation in the AI security space is inevitable, with larger cybersecurity players like Palo Alto Networks and CrowdStrike likely to acquire specialized startups. Second, regulatory scrutiny will intensify, particularly in sectors like finance and healthcare, where AI-driven decisions have real-world consequences. Third, the integration of AI security into existing developer toolchains will become standard, with vendors like GitHub and GitLab embedding security checks into their platforms. For enterprises, the message is clear: securing AI is not a one-time project but an ongoing discipline. Companies that delay will face not only financial risks but also reputational damage in an era where trust in AI is paramount.