Y Combinator (YC) is an American technology startup accelerator and venture capital firm that provides seed funding, mentorship, and resources to early-stage startups. Founded in March 2005 by Paul Graham, Jessica Livingston, Robert Tappan Morris, and Trevor Blackwell, YC has funded over 5,000 companies across various sectors. YC's intensive three-month program, run four times a year, is designed to help startups refine their products, business models, and fundraising capabilities. The program culminates in a Demo Day, where startups present to a large audience of investors.
YC's current President and CEO is Garry Tan. The company's investment strategy focuses on sectors with high potential for innovation and disruption, with recent priorities including AI, climate tech, B2B software, and government solutions. In 2026, YC announced that startups can now receive their $500,000 investments in USDC stablecoins across Ethereum, Base, and Solana. YC's portfolio includes notable companies like Airbnb, Stripe, Reddit, Dropbox, and DoorDash. As of 2025, YC-backed companies have a combined valuation exceeding $600 billion.