AfterQuery Emerges as Y Combinator’s Swiftest Unicorn, Surpassing $3.2 Billion Valuation
AI training-data company AfterQuery has successfully completed a funding round that has raised its valuation to $3.2 billion. This milestone comes just five months after the firm secured a $30 million Series A funding, which valued the company at $300 million in April.
This impressive growth represents over a tenfold increase in valuation within a mere six months. Gustaf Alströmer, a partner at Y Combinator, noted that this is the quickest ascent to unicorn status for any startup in the accelerator’s history. The founders of AfterQuery, aged 22 and 23, participated in Y Combinator’s Winter 2025 cohort, merely 18 months ago.
In its April announcement, the San Francisco-based startup revealed that it achieved an annualized revenue run rate of $100 million and is collaborating with some of the largest laboratories in the field. Among its clients are notable companies such as Nvidia, Legora, and the Korean AI organization Motif Technologies.
AfterQuery is part of a new wave of startups inspired by Mercor and Scale, utilizing knowledge professionals—including doctors, lawyers, and other specialists—for model training purposes. However, instead of focusing solely on ensuring accurate responses, AfterQuery trains models and agents to emulate the decision-making and task-completion processes of top professionals, aiming to “encode the patterns, decisions, and reasoning of the world’s best practitioners.”
The details of the funding round were first revealed by Forbes. AfterQuery was not available for immediate comment.
