Mercor raises $750M Series D at $20B valuation to expand agent evaluation

Mercor closed a $750 million Series D that combines new investor money with an employee tender offer. Benchmark, General Catalyst, Felicis, Sapphire Ventures and several other funds took part alongside Nvidia, Salesforce and Zoom. The $20 billion valuation compares with $10 billion in October 2025. The company says the capital will expand infrastructure for model evaluations and post-training, along with environments where agents can learn complex multi-step workflows.

Mercor began by building testing infrastructure for frontier labs and is now selling similar tools to enterprises in every industry. It opened offices in New York and London this year to sit closer to enterprise and lab customers.

For AI founders, this shows that evaluation and training environments have become a funded category of their own. Teams shipping agents will face more buyers asking for measured reliability on their own workflows, which makes evaluation tooling a real line item rather than an internal side project.