AfterQuery surpasses $3.2 billion valuation, becomes y combinator's fastest unicorn

AI training-data startup AfterQuery has surpassed a $3.2 billion valuation, becoming Y Combinator’s fastest unicorn to date. The company reportedly raised a round that valued it at this level just five months after securing a $30 million Series A at a $300 million valuation in April 2026. According to Y Combinator partner Gustaf Alströmer, this marks the quickest ascent to unicorn status in the accelerator’s history. The founders, aged 22 and 23, were part of Y Combinator’s Winter 2025 cohort, 18 months prior. AfterQuery, based in San Francisco, reported an annualized revenue run rate of $100 million in April 2026, with clients including Nvidia, Legora, and Motif Technologies. The startup focuses on training models and agents to emulate professionals like doctors and lawyers, emphasizing the encoding of decision-making patterns and reasoning from top practitioners. Forbes first reported the funding round, though AfterQuery could not be reached for comment.