Saudi Sisters Wield $50 Billion Fortune as Global Power Brokers (1)

When President Donald Trump feted Saudi Arabia’s crown prince at a state dinner last month, invitees included heavyweights like Apple Inc.’s Tim Cook and Citigroup Inc.’s Jane Fraser. Seated next to Elon Musk was Lubna Olayan, whose deep connections to both Wall Street and the kingdom marked her out as one of the most influential people in a room packed with luminaries.

That White House banquet underscored the growing influence of the Olayan Group, a sprawling and secretive Saudi empire that Lubna and her sister Hutham have helmed for decades. The duo came of age at ...