AfterQuery reportedly becomes Y Combinator’s fastest-ever unicorn, now valued at $3.2B

AI training-data startup AfterQuery has reportedly secured a funding round valuing the company at $3.2 billion, just five months after its $30 million Series A round in April. According to Y Combinator partner Gustaf Alströmer, this is the fastest a startup has reached unicorn status in the accelerator's history. The founders, aged 22 and 23, participated in Y Combinator’s Winter 2025 cohort just 18 months ago. In April, the San Francisco-based startup reported an annualized revenue run rate of $100 million and confirmed partnerships with major industry players, including Nvidia, Legora, and Motif Technologies. AfterQuery distinguishes itself by employing knowledge professionals—such as doctors and lawyers—to train AI models. Rather than focusing solely on factual accuracy, the company aims to encode the patterns, decisions, and reasoning of world-class practitioners into AI agents to complete complex professional tasks.