Birds of a Y Combinator feather flock together.

Y Combinator president Sam Altman just led a massive $50 million Series B round for social news site Reddit, an early YC graduate out of the same 2004 class as Altman’s own Loopt.

This marks Altman’s 24th investment in a Y Combinator alum.

The Y Combinator folks are a tight-knit group – Altman’s top three most frequent co-investors are YC partners Paul Buchheit (15 shared investments), Alexis Ohanian (14), and Garry Tan (10). He’s invested alongside YC itself in another 9 rounds.

Altman is by no means the only YC partner to individually back YC alums on a regular basis – Ohanian has joined in with YC in 37 venture rounds and Buchheit another 28. Both have participated in over 25 follow-on rounds for startups previously funded by the seed accelerator.

Outside of the family, SV Angel and Andreessen Horowitz are the most eager to pick up where Y Combinator left off. Along with co-investing frequently with YC, SV Angel has piggy-backed the Silicon Valley accelerator in follow-on rounds for 59 YC companies, and a16z has done the same for another 38.

Check out CrunchBase Graph Insights and the CrunchBase Investor Leaderboard to discover some of your own connections.

Photo via Flickr user Ias-initially

  • Originally published October 1, 2014, updated April 26, 2023