AI security startup Onyx raises $113 million Series B at $640 million valuation

Israeli AI security startup Onyx Security has raised $113 million in a Series B funding round led by Bessemer Venture Partners, valuing the company at an estimated $640 million, the company announced. The financing comes just four months after Onyx emerged from stealth with $40 million in combined seed and Series A funding. The new funding will be used to accelerate development of the company's next-generation AI models and expand its sales, business development, and marketing operations in the United States and other international markets. Onyx develops a platform that enables enterprises to deploy AI agents securely by managing permissions, monitoring agent activity, and preventing risks associated with autonomous AI systems. Founded in 2024 by Maxim Bar Kogan and Gil Elbaz, Onyx now employs more than 80 people across Israel, the United States, and Canada and works with several Fortune 500 customers. In June, Anthropic announced it had integrated Onyx's technology to help enterprise customers adopt AI securely. Co-founder and CEO Maxim Bar Kogan said demand exceeded expectations after the company emerged from stealth, creating tremendous investor interest and allowing the firm to raise the round much sooner than expected. He said the financing size reflects investors' conviction that AI security will become one of cybersecurity's most important markets.