AfterQuery, an AI training data startup, has reportedly raised a round worth $3.2 billion. This comes just five months after announcing a $30 million Series A in April at a valuation of $300 million.
This is a more than 10x increase in less than six months, and Y Combinator partner Gustaf Alströmer says it’s the fastest time in the accelerator’s history for a startup to go from launch to unicorn status. The AfterQuery founders are now 22 and 23 years old and joined Y Combinator’s Winter 2025 cohort just 18 months ago.
The San Francisco startup announced in April that it had an annual revenue run rate of $100 million and was working with a number of major research labs. It counts companies such as Nvidia, Legora, and South Korean AI research institute Motif Technologies as customers.
AfterQuery is one of several startups following Mercor and Scale that hire knowledge experts such as doctors, lawyers, and other experts to train their models. However, rather than guaranteeing that models will answer questions accurately, AfterQuery trains models and agents on how to work the same way experts complete tasks, in a way that the company describes as “encoding the patterns, decisions, and reasoning of the world’s best practitioners.”
Forbes first reported the round. AfterQuery could not be reached for comment.
