An AI Training Data Startup Just Became Y Combinator’s Fastest-Ever Unicorn

AfterQuery, an 18-month-old AI startup, has reached a $3.2 billion valuation in a brand new funding spherical, Forbes reported Monday. That determine is greater than ten instances the $300 million valuation it carried 5 months earlier, when it closed a $30 million Sequence A—an early funding spherical the place a startup sells a slice of itself for progress capital.

The leap makes AfterQuery the quickest startup in Y Combinator’s historical past to go from inception to unicorn standing, in response to YC associate Gustaf Alströmer. AfterQuery declined to touch upon the report. One in all Forbes‘ sources stated the corporate is already worthwhile and has lined up a lead investor for the spherical.

Spencer Mateega and Carlos Georgescu based the corporate in February 2025, 18 months after becoming a member of Y Combinator’s Winter 2025 batch as two highschool mates with no product and no mounted thought. Mateega posted on X in July that annual recurring income—the yearly worth of an organization’s ongoing subscriptions—had grown to the “tons of of thousands and thousands,” up from $100 million in April.

The founders initially needed to construct AI brokers for finance. Testing confirmed main fashions stored failing at nuanced, professional-grade calls—not from lack of uncooked functionality, however as a result of nobody had ever taught them how an professional truly causes by a tough resolution.

In order that they pivoted. AfterQuery now pays specialists to provide reasoning knowledge: written, step-by-step information of how an expert works by an issue, used to show AI fashions judgment as a substitute of simply information. Nvidia has used that knowledge to coach its open-source Nemotron fashions, and AfterQuery additionally counts former OpenAI CTO Mira Murati’s Considering Machines Lab and authorized AI agency Legora as purchasers, per Forbes.

The demand behind that pivot is industry-wide. Frontier labs—the businesses constructing essentially the most superior AI methods—have already picked by a lot of the usable textual content on the open net, and artificial knowledge, or AI-generated coaching materials, solely goes thus far. What’s left briefly provide is judgment that solely comes from actual, credentialed consultants.

Different firms are chasing the identical scarcity from totally different instructions. South Korean fintech Toss lately opened its 30 million customers to the AI data economy by a partnership with knowledge infrastructure agency Poseidon, paying abnormal customers to report real-world knowledge that fashions cannot discover on-line.

AfterQuery is not the one one cashing in on the scarcity. Scale AI’s Alexandr Wang grew to become the {industry}’s first data-labeling billionaire in 2021 at age 24, earlier than Meta paid $14.3 billion for a 49% stake and put Wang atop its personal AI lab. Rival Mercor’s founders handed Wang’s early report final October, changing into billionaires at 22.

Mateega has stated AfterQuery’s edge over Mercor, which leans on an AI interviewer to employees a big contractor pool, is customized software program that screens submissions for a “Goldilocks” issue—laborious sufficient to problem a frontier mannequin, not so laborious it might probably’t study from the reply. AfterQuery additionally trains its personal fashions on the information earlier than promoting it, to indicate labs the fabric truly strikes the needle reasonably than asking them to take its phrase for it.

Mercor, for its half, is at the moment in talks with Nvidia for a funding spherical that may worth it at $20 billion, doubling its $10 billion price ticket from final October. AfterQuery’s spherical has but to shut, and the corporate has not named its lead investor.