F5 Acquires CalypsoAI for $180M to Boost AI Enterprise Security

F5 paying $180M to acquire CalypsoAI to boost AI enterprise security offerings

Seattle-based security and application delivery giant F5 will pay $180 million to acquire CalypsoAI, a startup founded in 2018 that helps companies secure their generative AI infrastructure. The deal is financed primarily with cash and is expected to close this month, F5 said in a news release. Founded in 2018 with offices in Ireland and New York City, Calypso provides real-time threat defense and other data security products to customers deploying AI-related workloads. "AI is redefining enterprise architecture -- and the attack surface companies must defend," François Locoh-Donou, president and CEO of F5, said in a statement. CalypsoAI raised $23 million in 2023. Its backers include Paladin Capital Group; Lockheed Martin Ventures; Hakluyt Capital; Expeditions Fund; and others. "Our customers rely on us to pressure test AI systems at scale, set inference layer guardrails that adapt as models change, and to gain visibility and auditability across their AI estate," CalypsoAI CEO Donnchadh Casey said in a statement. Funding to cybersecurity startups reached a three-year high in the first half of 2025. F5 acquired San Francisco cybersecurity startup Fletch in June and swooped up observability company MantisNet in August. F5 topped estimates for its fiscal third quarter, with revenue up 12% to $780 million. GAAP net income was $190 million, up from $144 million. The company's stock is up more than 30% this year.

F5 to acquire Irish-led cyber start-up CalypsoAI for $180m

F5 said the deal is expected to close in its fourth-quarter fiscal year 2025, which concludes at the end of this month. App security company F5 has announced today (11 September) its intention to acquire Irish-led US start-up CalypsoAI for $180m. F5 hopes to integrate the start-up's AI security capabilities - including real-time threat defence, red-teaming tests and data security - into its Application Delivery and Security Platform as part of its goal of creating the "most complete solution for securing AI inference". "AI is redefining enterprise architecture - and the attack surface companies must defend," said F5 president and CEO, François Locoh-Donou. "Traditional firewalls and point solutions can't keep up. The addition of CalypsoAI will give enterprises the confidence to innovate faster and better protect critical data as they rely on F5 to deliver and secure apps, APIs, and AI models across their environment." As part of the deal, which is subject to customary closing conditions, F5 will acquire all issued and outstanding shares of CalypsoAI. The deal is expected to close in F5's fourth-quarter fiscal year 2025, which concludes at the end of this month. CalypsoAI, which was founded in 2018 and is headquartered in Dublin and New York, is led by two Irishmen: CEO Donnchadh Casey and president and chief technology officer James White. The start-up's flagship product is its Inference Platform, which, according to CalpysoAI, provides companies real-time visibility and enforcement at decision-making points. Earlier this year, the start-up secured $5m in funding after making it to the final round of cybersecurity innovation competition RSAC 2025 Innovation Sandbox after showcasing the platform. The company was named as a top-two finalist at the conclusion of the competition later that month. According to the company, the platform continuously tests, observes, and defends AI systems in both training and post-training environments, helping security leaders stay ahead of threats, meet governance requirements and scale AI responsibly. "Enterprises want to move fast with AI while reducing the risk of data leaks, unsafe outputs, or compliance failures," said Casey. "Our customers rely on us to pressure test AI systems at scale, set inference layer guardrails that adapt as models change, and to gain visibility and auditability across their AI estate. "F5 and CalypsoAI are more than the sum of their parts: high-performance application delivery and AI security that enable businesses to deliver innovation faster without increasing risk." CalypsoAI cemented its presence in Ireland in June 2023, when it opened a Dublin-based centre of excellence and announced plans to more than double its Ireland-based headcount. In October 2024, the start-up announced plans to double its Ireland-based headcount again from 50 to 100 professionals. Don't miss out on the knowledge you need to succeed. Sign up for the Daily Brief, Silicon Republic's digest of need-to-know sci-tech news.

F5 acquires AI security provider CalypsoAI for $180M - SiliconANGLE

F5 Inc. today announced plans to acquire CalypsoAI Inc., a startup that helps enterprises protect their artificial intelligence applications from hackers. The all-cash deal values CalypsoAI at $180 million. That's more than four times the amount of funding the company raised prior to the acquisition. F5 expects to close the transaction later this month. Nasdaq-listed F5 provides software that companies use to secure their applications and increase their performance. It also makes physical appliances that can optimize the flow of network traffic in data centers. F5 generated $780 million in revenue last quarter, 12% more than the same time a year earlier. CalypsoAI, for its part, has built a cybersecurity toolkit called the Inference Platform that is optimized to protect AI workloads. It uses AI agents to generate prompts that mimic the malicious input hackers might attempt to enter into an application. If a prompt is blocked, the Inference Platform can adapt its behavior and try again. Companies can use the software to determine whether an AI workload could be tricked into leaking sensitive data. According to CalypsoAI, its software also spots other vulnerabilities. It can check whether malicious prompts might cause an AI application to crash or slow down. The Inference Platform includes a tool called Defend that enables enterprises to create guardrails for their applications. A bank, for example, could implement controls that prevent a support chatbot from disclosing credit card numbers. CalypsoAI says that the tool lends itself to blocking not only data theft but also AI output that might breach regulations. The third component of the company's platform is called Observe. According to CalypsoAI, the tool monitors how users interact with an AI application and collects technical data on cybersecurity incidents. "AI is redefining enterprise architecture -- and the attack surface companies must defend," said F5 Chief Executive Officer François Locoh-Donou. "Traditional firewalls and point solutions can't keep up." F5 plans to integrate the Inference Platform into the F5 Application Delivery and Security Platform, a product suite that includes many of its core offerings. CalypsoAI's software will complement the existing cybersecurity features in the bundle. F5 provides tools that can help companies spot vulnerabilities in their applications, block distributed denial-of-service attacks and perform related tasks.

F5 To Acquire CalypsoAI For GenAI Security Push

The $180 million deal aims to boost AI security on the F5 Application Delivery and Security Platform, the company says. F5 announced Thursday it plans to acquire AI security vendor CalypsoAI for $180 million. The deal, which mainly consists of cash, is expected to close during the fourth quarter of F5's fiscal 2025, ended Sept. 30. [Related: F5 Unleashes AI Assistant To Ease Operations Burden For NetOps, SecOps, DevOps] The planned acquisition aims to boost AI security on the F5 Application Delivery and Security Platform, the company said. CalypsoAI, which was founded in 2018, is a "pioneer" in the area of enterprise AI security, F5 said in a news release. Key capabilities offered by CalypsoAI include real-time protection against threats targeting AI applications and models, such as prompt injection and jailbreaking, according to F5. Other key functionality includes guardrails for detection and prevention of leakage of sensitive data as well as policy violations, F5 said. The deal follows acquisitions by F5 earlier this year including agentic-powered security startup Fletch in June and real-time network observability vendor MantisNet in August. In an interview with CRN in March, F5 CEO François Locoh-Donou pointed to the widespread impacts of AI on how enterprises are handling their IT and security obligations. For instance, the massive adoption of AI has led enterprises to get "smarter" about where to put their application workloads, prompting a new cloud repatriation movement, Locoh-Donou said.

F5, Inc. signed a letter of intent to acquire Calypso AI Corp for $180 million.

F5, Inc. (NasdaqGS:FFIV) signed a letter of intent to acquire Calypso AI Corp for $180 million on September 11, 2025. The consideration will be financed primarily with cash. The acquisition is subject to customary closing conditions. The expected completion of the transaction is in F5?s fourth quarter fiscal year 2025, ending September 30, 2025. Foros Advisors LLC acted as financial advisor for F5, Inc. Sullivan & Cromwell LLP acted as legal advisor for F5, Inc. Cooley LLP acted as legal advisor for Calypso AI Corp.