The acquisition of Sprint Corp. was supposed to help Masayoshi Son realize his vision of transforming SoftBank Group Corp. into the world's most valuable company. Instead, the 2013 deal has become his biggest setback so far, dragging down SoftBank shares and cutting into the billionaire's wealth.
SoftBank dropped 7.9 percent in Tokyo on Monday to ¥5,111, falling to its lowest level since it closed the Sprint deal 2½ years ago. Son's fortune has shrunk by $3.2 billion over the past 12 months, according to the Bloomberg Billionaires Index, as the Japanese company's stock plunged.
The Sprint deal has proven a dramatic blow for Son, one of the nation's most enigmatic entrepreneurs who has said he has a 300-year plan for SoftBank and wants to build an Internet empire unrivaled in "profit, cash flow and market value." Instead, as Sprint losses mounted, Son found himself spending hours a night on the phone with its engineers and executives. The prospects of a turnaround may be slipping away, taking away precious time from the 58-year-old as he tries to secure his legacy.