Micro1 raises $100M at $4B as expert data for post-training booms

Forbes reported that annual recurring revenue grew from $7 million at the start of 2025 to over $500 million by September 2026. The new valuation is eight times the $500 million set in September 2025. Customers include frontier AI labs, Microsoft, Amazon and the robotics firm 1X. Two xAI cofounders invested in the round. Two frontier labs reportedly took part as well. Experts such as doctors, lawyers and software engineers are screened by an in-house AI interviewer called Zara. The pivot began when another data-labeling company asked Micro1 to recruit hundreds of engineers. The founder, Ali Ansari, then saw more value in supplying labs with training and evaluation data than in placement fees. Snorkel AI, the other large data round this week, raised $350M at a $3.5B valuation and reported a $375 million annualized revenue run rate. Firecrawl and AfterQuery are also selling data to frontier labs. For AI founders, expert data is now a large, fast-growing line item for frontier labs, and investors are pricing it like infrastructure. Margins are the open question. Snorkel has not disclosed what delivering expert work costs it, and Micro1 pays contracted experts too. Companies buying data should expect vendors to be well funded and capacity-constrained, and those building in this space face rivals with large balance sheets.