The Walton family, world’s richest family and the owners of US retail giant Wal-Mart, lost $3.2 billion after Wal-Mart’s shares dropped 3.1% on Thursday as sales fell short of expectations. The Walton family fortune estimated at $130 billion is primarily held by the founder Sam Walton’s three children, Rob, Jim and Alice, daughter-in-law Christy and her son, Lukas.