AfterQuery Reportedly Hits $3.2B Valuation, Becoming Y Combinator’s Fastest-Ever Unicorn

AfterQuery has reportedly raised a round valuing the AI training-data startup at $3.2 billion. The new valuation comes just five months after the company announced a $30 million Series A at a $300 million valuation in April. TechCrunch notes that this represents more than a 10x increase in less than half a year.

According to Y Combinator partner Gustaf Alströmer, AfterQuery is the fastest startup to go from launch to unicorn status in the accelerator’s history. The company’s founders, now 22 and 23, attended Y Combinator’s Winter 2025 cohort 18 months ago. That timeline makes the reported fundraise notable even in a venture market already focused heavily on AI.

AfterQuery is part of a group of startups using knowledge professionals, including doctors, lawyers, and other specialists, for model training. The company differs from approaches focused mainly on answer accuracy by training models and agents to work through tasks like professionals would. It describes this as encoding the patterns, decisions, and reasoning of top practitioners.

In April, the San Francisco startup said it had reached a $100 million annualized revenue run rate and was working with many of the biggest labs. It has named Nvidia, Legora, and Korean AI lab Motif Technologies as customers. Forbes first reported the round, and AfterQuery could not be immediately reached for comment.