AfterQuery Becomes Y Combinator's Fastest Unicorn

AfterQuery, a San Francisco startup barely 18 months out of Y Combinator, has reached a $3.2 billion valuation. That is up from $300 million just five months ago, and it makes the company the fastest business ever to go from launch to unicorn in the accelerator's history, according to YC partner Gustaf Alstromer.

The founders, aged 22 and 23, went through YC's Winter 2025 batch. Their business is unglamorous and very much of the moment. They pay doctors, lawyers, engineers and financial analysts to produce the kind of expert judgement that AI labs can no longer scrape off the open web.

That is the crux of why the valuation moved so fast. The big labs have largely exhausted the freely available internet as training material, and the next round of gains depends on harder-to-get data: worked reasoning from people who actually know a field. AfterQuery sells exactly that. By April it reported an annualised revenue run rate of $100 million and named Nvidia, Legora and the Korean lab Motif Technologies among its customers.

The data bottleneck

AfterQuery's rise is a useful read on where the money is flowing. For a while the working assumption was that scale alone would carry model quality forward. As the easy text ran out, attention shifted to the quality and specificity of what goes in. Human expertise, captured and labelled, has become one of the scarcer inputs in the whole pipeline, and investors are paying accordingly.

There is a caveat worth keeping in view. A valuation that multiplies more than tenfold in five months prices in a lot of future growth, and the market for training data is young enough that today's leaders are not guaranteed to stay ahead. For now, though, a company that essentially resells human judgement is one of the hottest names in the sector, which tells you something about the state of the models buying it.