12. Stefan Persson
Estimated net worth: $28 billion
Persson (right) is chairman of clothing company Hennes & Mauritz, H&M.
11. Christy R. Walton and family
Estimated net worth: $28.2 billion
Walton was the richest woman on the Bloomberg list of billionaires in 2012. Walton is the widow of John Walton, a son of Walmart founder Sam Walton. Forbes profile