Walmart heir Lukas Walton and his wife just bought a minority stake in the NBA franchise and its home court, the United Center. ‘This transaction reflects our dedication to the city’s future,’ the couple said. Walmart is bullish on Chicago. Billionaire Lukas Walton, the 39-year-old heir to the world’s largest retailer, and his wife, Samantha, have acquired a minority stake in the Chicago Bulls and the United Center, the Near West Side home of the NBA franchise and the NHL’s Chicago Blackhawks.