The past 12 months have been tumultuous for Mr Son and SoftBank. A year ago, the company unveiled a record buyback, sparking a rally that pushed shares to the highest since its dot-com peak in 2000. Uber Technologies' disappointing public debut and the implosion of WeWork wiped out the gains over the next few months. But SoftBank surged again this month after Mr Singer disclosed his stake and Mr Son won approval to sell his Sprint Corp to T-Mobile US. SoftBank has 13.75 trillion yen of interest-bearing debt, with more than 2.6 trillion yen of bonds coming due in the next three years. The company also had 3.8 trillion yen of cash and equivalents as of the end of December. BLOOMBERG