Ali Ansari turned a small AI-recruiting business into a $4 billion data-labeling startup in about a year. Micro1 has closed a Series B raise of more than $100 million at that valuation, according to Forbes and TechCrunch -- eight times the $500 million price its Series A set in September 2025. Frontier AI labs, Microsoft, Amazon and humanoid-robotics maker 1X are among its customers, with several of them participating in the new round, including two frontier labs and two of xAI's co-founders, per Forbes. The business itself has broadened past its recruiting-platform roots: alongside contract evaluations of model outputs and human-labeled training sets, Micro1 now sells synthetic data and "reinforcement learning gyms" -- simulated environments built from real enterprise data where AI agents practice navigating a workplace before they're deployed into one.
Micro1's three $500-million-ish numbers, and what each one is
- $500M · Valuation, Sept. 2025
- Micro1's Series A price tag, one year before this raise
Includes: What investors priced the whole company at a year ago
Excludes: Any revenue figure -- this is a valuation, not a sales number - $500M · Gross annualized revenue, Aug. 2026
- Micro1's own disclosed run-rate, a month before the raise
Includes: All revenue booked before paying the people and vendors who supply the actual labeled data
Excludes: The 30-40% Micro1 says goes straight back out to data providers - $4B · Valuation, Sept. 2026 (this raise)
- What the new Series B prices the company at
Includes: The full company, per the new round's terms
Excludes: The raise amount itself, which every outlet reports only as "over $100 million"
The distinction matters because “gross annualized revenue” is doing a lot of work in a business that pays most of its actual labelers and data providers out of that top line. Ansari told TechCrunch in August that Micro1 keeps 60% to 70% of gross revenue after those costs on its highest-margin work -- meaning 30% to 40% goes straight back out to the data providers and labelers who did the actual work -- meaning the business's real size, by net revenue, likely runs closer to $300-350 million a year than the $500 million headline. That still trails competitors Mercor ($2 billion gross run rate) and Handshake ($1 billion), which Ansari himself named as the market Micro1 is chasing.
Ansari has also drawn a line his rivals reportedly haven't: he told TechCrunch Micro1 doesn't sell its training data to Chinese model makers, contrasting the company with competitors that do. Whether that stance survives contact with a $4 billion valuation and a fresh set of outside investors is one of the more concrete things to watch as the company scales. For now, the raise is a bet that the AI industry's hunger for the human-generated data underneath every frontier model -- graded conversations, labeled images, workplace simulations -- is growing at least as fast as the models trained on it.
- Micro1's Series B closed above $100 million at a $4 billion valuation, per Forbes and TechCrunch.
- That's 8x the startup's $500 million valuation from its September 2025 Series A.
- The company reports $500 million in gross annualized revenue but keeps only 60-70% after data-provider costs.
- Founder Ali Ansari says Micro1 won't sell training data to Chinese model makers, unlike some rivals.
- None of the funding figures are independently confirmed beyond the company's own and reporters' accounts.