Walmart heir Rob Walton just retired from the retailer's board after 4 decades. He and his 2 siblings are worth a combined $228 billion — more than Jeff Bezos or Elon Musk.

• Walmart heir Rob Walton just stepped down from the retailer's board after four decades.
• He and his two siblings have added more than $100 billion to their net worth in recent years.
• Their gains have been fueled by Walmart stock, which hit a record high in March.

Walmart heir Rob Walton just stepped down from the retailer's board after four decades. He and his two siblings have more than doubled their money since 2016, adding more than $100 billion to their combined fortunes.