Twitter IPO: who will get rich? Jack Dorsey - holds 23,411,350 shares, or 4.9pc Dorsey co-founded Twitter and still serves as its chairman. In 2009, he founded payments service Square and serves as its CEO. Dick Costolo - holds 7,589,608 shares, or 1.6pc A onetime improvisational comedian, Costolo took the helm of Twitter in 2010. He joined Twitter as COO the year before, after he and co-founders sold their web feed management provider FeedBurner to Google in 2007. Adam Bain - holds 1,722,350 shares, or less than 1pc Bain is the president of global revenue at Twitter. He was formerly the president of audience network at News Corp's Fox Interactive Media. David Rosenblatt - holds 283,333 shares, or less than 1pc Rosenblatt is the CEO of luxury online retailer 1stdibs.com and is a member of Twitter's board of directors. The following groups own at least 5pc Rizvi Traverse Management A closely held private-equity fund based in Michigan, Rizvi has made a name for itself by buying stakes in entertainment companies such as Playboy and movie producer Summit Entertainment. Last year, it led a $200m funding round in Jack Dorsey's payments company, Square. Spark Capital Venture firm Spark started investing in Twitter in 2008. For a time, Spark partner Bijan Sabet served on Twitter's board. Union Square Ventures Venture firm Union Square started investing in Twitter in 2008. For a time, USV partner Fred Wilson served on Twitter's board. DST Global The investment firm founded by Russian billionaire Yuri Milner led a $400m investment in Twitter in 2011. At the time, Twitter was valued at around $8bn.