Ex-Anthropic staffers’ AI startup Mirendil seeks $5B valuation just months after launch

Mirendil, a San Francisco startup founded by former Anthropic researchers, is negotiating a funding round that would value the company at $5 billion. The company is looking to raise up to $1 billion, with Kleiner Perkins reportedly leading the round and Andreessen Horowitz (a16z) participating. To put the speed of this ascent in perspective: Mirendil raised a $200 million seed round at a $1 billion valuation roughly three months ago. A 5x valuation jump in a single quarter is the kind of trajectory that makes even seasoned venture capitalists do a double take. From Anthropic’s lab to a billion-dollar company Mirendil was founded in December 2025 by Behnam Neyshabur and Harsh Mehta, both former researchers at Anthropic. Neyshabur previously co-led the scientific AI reasoning team there, while Mehta served as a senior research scientist. The founding team numbers around 20 specialists drawn from top-tier AI organizations. The company’s earlier seed round, completed in June 2026, was co-led by a16z and Kleiner Perkins, with NVIDIA also chipping in. What Mirendil is actually building The startup’s core mission is developing self-improving AI systems designed to automate complex AI rese...