Hedge fund reports 5.07% passive stake in ZyngaOct. 21, 2013 4:35 PM ET|About: Zynga (ZNGA)|By: Eric Jhonsa, SA News Editor Robert Pitts' Steadfast Capital has disclosed a 31.5M-share (5.07%) passive stake in Zynga (ZNGA). Steadfast joins Barry Rosenstein's Jana Partners in owning a large piece of the struggling social game developer. (13G) ZNGA +1.1% AH. Q3 results arrive on Thursday.