Jim Walton's net worth has surpassed $100 billion.Rick T. Wilking/Stringer/Getty ImagesJim Walton's net worth just passed $100 billion for the first time.The Walmart heir's wealth has surged by $28 billion this year due to the retailer's soaring stock.His brother and sister, Rob and Alice Walton, are on the brink of becoming centibillionaires too.Jim Walton is the newest member of the $100 billion club.The Walmart heir's personal fortune reached 12 digits for the first time on Wednesday, ranking him 13th on the Bloomberg Billionaires Index.