Nelson Peltz speaking at the 2019 Delivering Alpha conference in New York on Sept. 19, 2019.Nelson Peltz is stepping down as chair of Wendy's, ending a 17-year reign at the fast-food chain.Wendy's said Friday that the change is effective immediately.Peltz's exit comes as low-income consumers eat out less, causing Wendy's sales to slump. Shares of the burger chain have fallen more than 12% this year, dragging its market value down to $3.45 billion. Earlier this year, PepsiCo veteran Kirk Tanner stepped in as ...