Jim Simons, the founder of Renaissance Technologies, urged Robert Mercer to step down from his role as co-chief executive officer over concerns that his backing of Breitbart News was hurting morale at the world’s most profitable hedge fund, according to people familiar with the matter.
In recent months, Mercer’s personal political projects dragged the secretive firm into the national spotlight. Mercer and his daughter, Rebekah, are prominent Republican donors and patrons of Stephen Bannon, chairman of Breitbart News, a website that backs the nationalist movement that helped elect President Donald Trump.
