Y Combinator funds pre-seed startups with a strong founding team, a clear product vision, and early traction, providing $500K in exchange for equity to accelerate growth. It exists to identify and support ambitious founders who can build a large company, offering mentorship, network, and a structured batch program to achieve product-market fit.

- Founder quality: clarity of vision, domain expertise, resilience, and ability to execute (single founders are a slight disadvantage but not disqualifying). - Traction: evidence of user growth, revenue, partnerships, or validated proof-of-concept (e.g., pre-registered results, named pharma partners). - Market size: large, growing, and addressable market (e.g., AI/biotech for addiction therapeutics). - Product uniqueness: clear technical advantage or SOTA over existing solutions (e.g., CCT model's 13-22pp super-additivity). - Scalability: potential to become a billion-dollar company, not a lifestyle business or consultancy. - Founder-market fit: deep understanding of the problem and customer (e.g., pharmacist + computational modeler). - Clarity of pitch: concise 1-minute video, compelling deck, and traction story that shows progress and ambition.

YC funds a wide range of startups, but typical archetypes include technical co-founders with a working prototype, early revenue or users, and a clear go-to-market plan. Notable examples in biotech/health include Benchling, Ginkgo Bioworks, and more recently AI-driven drug discovery startups like Recursion (though not YC). For 2026 batches, AI/ML startups with domain-specific applications are heavily favored.

A pair of co-founders (technical + business) with a working MVP, early traction (e.g., paying customers, pilot partnerships, or validated research results), a large addressable market, and a clear path to scale. The founder should be able to articulate a compelling vision in under 60 seconds and demonstrate relentless execution.