Few fortunes are as volatile as Masayoshi Son¡¯s.

The SoftBank Group Corp. founder was briefly richer than Bill Gates at the start of the century before tech stocks crashed. In March 2020, as markets sank under Covid-19 and questions swirled over SoftBank¡¯s investments, his wealth dipped to $8.4 billion, the lowest since 2016.

Less than a year later, Japan¡¯s second-richest person has more than quadrupled his fortune to $38 billion, according to the Bloomberg Billionaires Index, hitting the highest level since Bloomberg started tracking billionaire wealth in 2012.