Artificial intelligence training data company Mercor.io Corp. today revealed that it has raised $750 million in new funding at a $20 billion valuation.

Mercor provides the human expertise used to train and evaluate AI models, drawing on a network of more than 5 million domain experts. Most of that work so far has been for frontier AI labs. The new funding is aimed at taking it to enterprises in every industry, which Mercor argues need their own way to measure whether an AI agent can be trusted with a job.

Co-Chief Executive Brendan Foody said “every job in the economy” will need its own AI agents and that companies will need a way to train and evaluate them on their own work. Mercor spent the past two years building that infrastructure with the frontier labs. The lab business has grown fast. Foody said in a post on X in July that annualized revenue had passed $2 billion in June.

Adarsh Hiremath, Mercor’s other co-chief executive, said a model can score well on a public benchmark and still fail on “the systems, policies and edge cases that define how a specific business runs.” For each enterprise customer, Mercor builds a custom benchmark that measures models against that company’s own standards. Post-training starts from there.

Part of that post-training runs on software from Deeptune Inc. Mercor bought the New York startup in July, and its team had spent the two years before that recreating hundreds of enterprise applications for AI agents to practice on. The company said the new money will pay for research and evaluation infrastructure, including more of those environments.

Mercor did not name a lead investor for the Series D round, which drew corporate money from Nvidia Corp., Salesforce Inc. and Zoom Communications Inc. Returning investors Benchmark Capital Management Co., Felicis Ventures Management Co. and General Catalyst Group Management also participated. Other investors in the round were Fundomo, G Squared Equity Management LP, Glade Brook Capital Partners, Sapphire Ventures, StepStone Group Inc., XTX Ventures and funds managed by affiliates of Apollo Global Management Inc.

The last round came in October 2025, when Felicis led a $350 million Series C round that valued Mercor at $10 billion. Foody’s blog post on the new round says it included a tender offer for employee shares, and the company has not said how the $750 million splits between that and fresh capital.

Frontier labs have been the main buyers of expert-driven training data so far, according to Jai Das, president, partner and co-founder of Sapphire Ventures. He expects that to change as open models get good enough for enterprises to build on, saying Mercor has built “something hard to replicate” from several years of work with the labs.

Image: Mercor