Walton family members (L to R) Jim, Rob and Alice Walton speak onstage at the Wal-Mart annual meeting in Fayetteville, Arkansas, June 5, 2015. Wal-Mart Stores Inc named Vice Chairman Greg Penner as its new chairman on Friday, replacing his father-in-law Rob Walton and cementing the founding family's influence over the board of the world's largest retailer. REUTERS/Rick Wilking