As of May 2013, Y Combinator had funded over 500 startups.[20][21] The number of startups funded in each cycle has been gradually increasing. The first cycle, in summer 2005, had eight startups. In the summer 2012 cycle, there were more than 80. Y Combinator has since reduced their class size down to less than 50 with their winter 2013 batch, but they expect to grow it again.[22]

Some of the better-known funded companies include Scribd, reddit, Airbnb, Dropbox, Disqus and Heroku.[20]