Just five months after emerging from stealth with a $100 million Series A, synthetic-user startup Simile has closed a $200 million Series B at a $2 billion valuation, the company confirmed. The rapid fundraising underscores investor appetite for AI-powered market research tools that simulate human behavior at scale. Main Developments Greenoaks led the Series B round, with participation from Index Ventures, Hanabi, Bain Capital Ventures, A*, Factory, Definition, and CVS Health Ventures. CVS is not only an investor but also one of Simile's marquee customers. The startup's platform creates simulated users for marketing and product research, aiming to replace or augment traditional focus groups and surveys. Founder Joon Sung Park, a Stanford PhD graduate, built his dissertation around a project called Smallville, where AI agents simulated human-like social behaviors including hosting parties. That academic work now forms the technical foundation for Simile's commercial offering. Read also: Spotify's New User Notes Feature Turns Playlists Into Personal Diaries Background Simile debuted from stealth in early 2026 with a $100 million Series A led by Index Ventures. The company's stated mission—to simulate all eight billion people on earth accurately and honestly—has drawn skepticism, as market research traditionally relies on the unpredictability of real human emotion and reason. Nonetheless, the concept has attracted venture capital across the sector. Another startup in this space, Aaru, raised a Series A in December at a $1 billion valuation, signaling that investors see synthetic-user technology as a promising alternative to vibe coding for product mock-ups and consumer testing. Why It Matters Simile's valuation doubling in five months reflects a broader trend: venture firms are placing large bets on AI startups that promise to streamline or replace traditional research methods. If synthetic users can deliver reliable insights faster and cheaper than human panels, industries from retail to healthcare could reshape how they test products and marketing campaigns. CVS's dual role as investor and customer provides a real-world validation point, suggesting that even regulated industries see potential in simulated consumer data. However, the technology's ability to capture genuine human unpredictability remains an open question. What's Next With $300 million in total funding, Simile will likely expand its engineering team and customer base beyond early adopters like CVS. The company may also face pressure to demonstrate that its simulations produce commercially actionable results, especially as competitors like Aaru pursue similar goals. No timeline for product milestones or further fundraising has been announced.