SoftBank holds stakes in all of the world's biggest ride-hailing companies and scores of other high-profile startups. : The Japanese billionaire’s SoftBank Group Corp. reported operating income that more than tripled in the three months to March 31 to 494.9 billion yen ($4.5 billion), helped by a 418 billion yen gain on Uber Technologies Inc. SoftBank and its Vision Fund are the largest shareholders in the US ride-hailing giant, which is going public this week at a market value that may reach $79 billion.