How Softbank, World's Biggest Tech Investor, Throws Around Its Cash

Mr. Son paid it anyway. And he continued a buying spree, picking up stakes in dozens more companies, many of them "unicorns"--startups that have grown to valuations over $1 billion--such as Uber Technologies Inc. and WeWork Cos. In some of those deals, too, he had to argue with directors and advisers who thought he was paying too much. Investors want to understand just how Mr. Son goes about deciding on his billions of dollars of bets, among the largest in the tech industry, which he does through SoftBank and affiliated investment funds. Current and former SoftBank directors, executives, investing partners and others who know Mr. Son give a glimpse into how he works.