Y Combinator

Eras

• The Walk Home — On 11 March 2005, walking home from dinner in Harvard Square, Paul Graham and Jessica Livingston decide to start their own investment firm. Cambridge Seed becomes Y Combinator within days, and the Summer Founders Program invents the batch model.
• Go West — Reddit’s 2006 sale is the first big win. The batch model proves itself, the program moves to Silicon Valley, Hacker News launches, and a generation of founders — Dropbox, Airbnb — find their way to Mountain View.
• The Sequoia Era — The Cambridge program closes and YC consolidates in the Valley. Sequoia’s backing lets the batches grow; Stripe and Airbnb break out, Startup School scales to the biggest names in tech, and YC begins funding nonprofits.
• Altman & Scale — Sam Altman becomes president; the standard deal becomes $150k for 7%. The How to Start a Startup course puts YC’s playbook online, the batches grow into the hundreds, and Coinbase, DoorDash and Cruise arrive.
• The Ralston Years — Geoff Ralston takes over as president. YC runs its first fully remote batch through the pandemic, raises the standard deal to $500k, and a flood of online talks and founder stories carries YC’s ideas worldwide.
• Tan & the AI Era — Garry Tan becomes president and CEO and moves YC back to San Francisco. The AI wave reshapes every batch, the first AI Startup School fills a hall with 2,500 students, and at twenty years YC has funded over 5,000 companies worth a combined $600 billion.