AfterQuery Becomes Y Combinator’s Fastest Unicorn, Reaching a Valuation of $3.2 Billion

AfterQuery, a rising star in the realm of AI training data, has reportedly secured funding that elevates its valuation to $3.2 billion, just five months after announcing a $30 million Series A funding round which valued the company at $300 million in April.

This impressive growth signifies an extraordinary increase of more than 10 times within a mere six months, and as pointed out by Y Combinator partner Gustaf Alströmer, it represents the swiftest rise to unicorn status for any startup in the accelerator’s history. The founders of AfterQuery, aged 22 and 23, were part of Y Combinator’s Winter 2025 cohort just 18 months ago.

In April, the San Francisco-based firm reported an annual revenue run rate of $100 million and underscored its partnerships with leading laboratories. Its noteworthy clientele includes distinguished companies such as Nvidia, Legora, and Korea’s AI lab Motif Technologies.

AfterQuery is at the forefront of a new generation of startups inspired by Mercor and Scale, collaborating with professionals like doctors and lawyers for model training. Rather than simply offering accurate responses, AfterQuery strives to empower models and agents to function like seasoned experts, effectively executing tasks—what the company refers to as “encoding the patterns, decisions, and reasoning of the world’s most adept practitioners.”

Forbes was the first outlet to cover this funding round, and AfterQuery has yet to respond to requests for immediate comments.