Michael Seibel

Overview

Michael Seibel is a distinguished angel investor and former CEO of Y Combinator, a leading startup accelerator. He co-founded and served as CEO for two Y Combinator-backed startups: Justin.tv (later rebranded as Twitch) and Socialcam. Under his leadership, Socialcam was acquired by Autodesk in 2012 for $60 million, and Justin.tv evolved into Twitch, which was acquired by Amazon in 2014 for $970 million. These ventures underscore his expertise in scaling and exiting technology companies. In 2013, Seibel joined Y Combinator as a part-time partner, becoming the organization's first African-American partner in 2014. He was appointed CEO of the accelerator in 2016, where he played a pivotal role in expanding Y Combinator's reach and diversity initiatives. In March 2025, Seibel transitioned to a Partner Emeritus role, allowing him to focus more on direct mentorship and investment activities. Throughout his career, Seibel has been an active angel investor, supporting numerous startups across various stages and industries. His investment portfolio includes companies such as Reddit, Cruise, Brex, Figma, Triplebyte, Captain 401k, Equipment Share, Pine Park Health, Promise, PayFazz, Easypost, Paystack, Mattermost, Rezi, Rippling, Zenysis, Jopwell, AptDeco, Magic, True Link, Wave, Scentbird, Squire, Bellabeat, Panorama Education, Arcus, Burrow, PeerWell, L., Give Campus, iLabservice, Lugg, Career Karma, Social Construct, Reach Labs, Grain, Aella Credit, Elpha, TIZETI, Wallets.ng, SketchDeck, Cambly, RankScience, Waystocap, Goodcover, CareRevolutions, Transcelestial, Better Health, Driver Technologies, Point, Newcraft, Qwest, Elpha, Vitable Health, Swipe Technologies, Evry Healthcare Inc, Clipboard Health, Taste Technologies, Inc., Bishop Fox, and Partnered. His strategic insights and commitment to fostering innovation have made him a respected figure in the venture capital community. Seibel's leadership at Y Combinator and his extensive investment experience have left a lasting impact on the startup ecosystem, particularly in promoting diversity and supporting underrepresented founders. His transition to Partner Emeritus marks a new chapter in his ongoing dedication to nurturing the next generation of entrepreneurs.