Michael Seibel (@mwseibel) — Twitter Score 307 out of 1000

Michael Seibel is a startup investor and Partner Emeritus at Y Combinator who co-founded Justin.tv / Twitch and Socialcam. Michael Seibel's Twitter Score is 307 out of 1000 (an Excellent rating) as of October 2026, ranking #1,023 (top 0.5%) among 497,973 tracked accounts.

Michael Seibel co-founded Justin.tv, which evolved into Twitch, the live-streaming platform that was acquired by Amazon for $970 million in 2014. He also co-founded Socialcam, which was sold to Autodesk for $60 million in 2012. Both ventures established him as a prominent figure in consumer internet and video streaming before he moved into early-stage investing.

Michael Seibel serves on the boards of Reddit, Dropbox, and Kalshi, the prediction markets platform. His work at Y Combinator has centered on advising and supporting early-stage founders across a wide range of sectors. Michael Seibel's account has 305,594 followers as of October 2026 and 6,281 posts, and has been active since 2007. He has been mentioned by 328 accounts, with 854 total mentions.

Who follows Michael Seibel on X?

The accounts that follow Michael Seibel include 1,787 founders, 491 angel investors, 195 influencers and 79 VCs. Among them are Balaji, Brian Armstrong, Nikita Bier, Sam Altman, Toly and Kyle Samani.