Simile raises $200M Series B at $2B valuation just five months after its Series A

Simile has joined the fast-moving ranks of AI unicorns, closing a $200 million Series B at a $2 billion valuation only five months after it emerged from stealth with a $100 million Series A. The Series B was led by Greenoaks, with participation from Index Ventures, Hanabi, Bain Capital Ventures, A*, Factory, Definition, and CVS Health Ventures — which is also one of Simile’s customers.

The startup builds simulated users for areas like marketing and product research. It was founded by Joon Sung Park, a Stanford PhD graduate whose dissertation involved a project called “Smallville,” in which AI agents carried on simulated human lives, down to holding parties.

Simile’s stated mission is to simulate “all eight billion people on earth, accurately and honestly” — a goal that is a stretch, since the entire reason companies conduct market research in the first place is that real humans are unpredictable, guided by both emotions and reason. Even so, simulating users for research is a promising area — akin to “vibe coding” for product mock-ups.

Simile isn’t the only startup in this space drawing investor attention. Aaru, for example, raised a Series A in December at a hefty “headline” $1 billion valuation.

Why it matters

The size and speed of Simile’s back-to-back rounds show investors are willing to pay steep valuations for AI tools that promise to shortcut expensive human research, even before the premise of simulating human behavior at scale is proven out.