AfterQuery hits $3.2B valuation in record time for Y Combinator

AfterQuery has reportedly closed a funding round that values the company at $3.2 billion, marking a tenfold increase in less than half a year. The startup, which emerged from Y Combinator's Winter 2025 cohort, achieved this milestone just five months after announcing a $30 million Series A at a $300 million valuation in April. According to Y Combinator partner Gustaf Alströmer, this trajectory makes AfterQuery the fastest startup in the accelerator's history to reach unicorn status.

Founded by two individuals now aged 22 and 23, AfterQuery operates in the rapidly expanding market of AI training data. While the company has reported an annualized revenue run rate of $100 million, its business model distinguishes it from earlier players like Scale AI or Mercor. Rather than focusing solely on verifying the accuracy of model outputs, AfterQuery specializes in training models and agents to execute complex tasks with professional-grade reasoning. The company describes its approach as "encoding the patterns, decisions, and reasoning of the world's best practitioners," leveraging knowledge professionals such as doctors and lawyers to simulate expert workflow patterns.

The startup has secured high-profile clients including Nvidia, Legora, and South Korea's Motif Technologies, suggesting that major labs are increasingly prioritizing task-completion capabilities over simple question-answering metrics. This shift reflects a broader trend in AI development toward building agents that can navigate multi-step professional environments. AfterQuery's rapid valuation growth underscores the high demand for high-quality, expert-derived training data as the industry moves beyond foundational model training into specialized application layers.