Blackberry co-founder (sold stock when iPhone launched), https://en.wikipedia.org/wiki/Douglas_Fregin
Facebook co-founder (pushed out), https://en.wikipedia.org/wiki/Eduardo_Saverin
MySpace founder (pushed out after sale), https://en.wikipedia.org/wiki/Tom_Anderson, "If you knew me before Myspace, you'd probably thought I'd have been a scholar teaching philosophy in a university my whole life. If you met me before college, you'd probably have thought I'd be a musician for my entire life ... I like change.