Micro1's Ali Ansari raises over $100M at $4B as the AI-training-data business passes $500M ARR
Forbes (Anna Tong)·medium signal
Forbes reports that Micro1, run by 25-year-old Ali Ansari, raised more than $100M at a $4B valuation, eight times its $500M valuation of September 2025. Revenue went from $7M ARR as a recruiting business in early 2025 to over $500M, and two frontier labs plus two xAI cofounders joined the round. This happened the same day Snorkel's $3.5B round was announced and in the same week Mercor contractors were fired for using AI to write training data, so money keeps pouring into human expert data even as its quality gets harder to police.