AfterQuery, an AI training-data startup, has reportedly raised a round that values it at a whopping $3.2 billion. This comes just five months after the company announced a $30 million Series A at a $300 million valuation back in April. In case you're doing the math, that's more than a 10x increase in under half a year - a growth rate that would make even a Silicon Valley hype man blush.

According to Y Combinator partner Gustaf Alströmer, this is the fastest any startup has gone from launch to unicorn status in the accelerator's history. The founders, who are currently 22 and 23 years old, were part of Y Combinator's Winter 2025 cohort just 18 months ago. Because nothing says 'seasoned entrepreneur' like being barely old enough to rent a car.

Back in April, the San Francisco-based startup boasted an annualized revenue run rate of $100 million and claimed to be working with some of the biggest labs in the field. Named customers include tech giants Nvidia, Legora, and Korean AI lab Motif Technologies. AfterQuery joins a new wave of startups - following in the footsteps of Mercor and Scale - that employ knowledge professionals like doctors, lawyers, and other specialists to train AI models. But unlike others that focus on making sure models answer questions correctly, AfterQuery trains models and agents to work like professionals would to complete tasks. The company describes this as 'encoding the patterns, decisions, and reasoning of the world’s best practitioners.' So basically, they're bottling expertise and selling it to machines.

Forbes first reported on this round, and AfterQuery could not be immediately reached for comment. Perhaps they were too busy counting their billions.