AfterQuery Achieves $3.2 Billion Valuation, Becomes Y Combinator’s Fastest Unicorn

AfterQuery, an emerging leader in the AI training data sector, has reportedly secured funding that boosts its valuation to $3.2 billion, just five months after revealing a $30 million Series A funding round that valued the company at $300 million in April.

This remarkable growth demonstrates an astonishing increase of over 10 times in just six months, and as noted by Y Combinator partner Gustaf Alströmer, it marks the fastest ascent to unicorn status for any startup in the accelerator’s history. The co-founders of AfterQuery, aged 22 and 23, were part of Y Combinator’s Winter 2025 cohort only 18 months prior.

In April, the San Francisco-based company announced an annual revenue run rate of $100 million and highlighted its collaborations with prominent laboratories. Its distinguished clientele includes renowned entities such as Nvidia, Legora, and Korea’s AI lab Motif Technologies.

AfterQuery is leading a new wave of startups inspired by Mercor and Scale, working alongside professionals like doctors and lawyers for model training. Rather than merely providing accurate answers, AfterQuery aims to empower models and agents to operate like seasoned experts, successfully executing tasks—what the company describes as “encoding the patterns, decisions, and reasoning of the world’s most skilled practitioners.”

Forbes was the first publication to report on this funding round, and AfterQuery has not yet responded to requests for immediate comments.