A 5-Month-Old Startup Just Raised $200M to Simulate All 8 Billion People on Earth

Simile, a simulation-AI company just five months old, has raised over $200 million at a $2 billion post-money valuation to build a foundation model for human behavior, one it says will eventually simulate all eight billion people on Earth. The round was led by Greenoaks, with Index Ventures doubling down and returning investors Hanabi, Bain Capital Ventures, A*, Factory, and CVS Health Ventures, plus Definition joining as a new backer.

For a company that launched less than half a year ago, the numbers are hard to ignore: revenue up fivefold, tens of millions of simulations already run for Fortune 100 enterprises, and a customer list that includes CVS Health, Wealthfront, Deloitte, and Gallup.

But the raise is not the real story. The idea underneath it is.

Simile is betting that AI has quietly moved the hardest problem in business. When anyone can use AI to create a product, a campaign, a policy, or a script in minutes, the bottleneck is no longer creation. It is judgment. The difficult question is no longer whether you can build something, but what you should build, for whom, and how it will land once it reaches real people.

Those are human questions. And most organizations still answer them the slow way, through surveys, focus groups, and educated guesses that take weeks and reach only a handful of people.

Simile’s answer is to simulate the human response before a single dollar is spent. Its foundation model for human behavior runs millions of scenarios to predict how people will react to a decision. Just as notably, the company has built a first-of-its-kind confidence model that scores how much to trust each simulation, a rare piece of intellectual honesty in a field prone to overpromising. It also released what it describes as the first product that lets organizations verifiably predict outcomes before acting.

That combination, ambition paired with a built-in accuracy check, is what appears to have won over both blue-chip customers and investors. Enterprises are already using the platform to strategize product launches, optimize customer experiences, and decide which new markets to enter.

The strategic implication for founders and executives is the part worth sitting with. Every major business decision is, at its core, a bet on how people will behave. Price this way, and customers churn. Launch in that market, and adoption stalls. Simile is trying to turn those bets into testable predictions, moving decision-making from instinct toward evidence.

The mission is deliberately audacious. Simulating eight billion people, accurately and honestly, is the kind of goal that invites skepticism, and the confidence model suggests the team knows it. Whether behavioral simulation becomes a genuine new category or a powerful tool inside existing workflows will be decided by how well those predictions hold up against reality.

For now, a 50-person team out of Palo Alto, including researcher Joon Sung Park, has a $2 billion valuation and a clear thesis: in a world where creation is free, the advantage belongs to whoever best understands what to create.

The companies that learn to simulate their decisions may soon outrun the ones still guessing. That is the race worth watching. Tech Lens Media.