Billionaire Masayoshi Son is poised to set another record — and not the good kind. When he reports earnings for the March quarter Thursday, SoftBank Group Corp.’s Vision Fund investment unit may have lost more money in one quarter than it ever has before.

The world’s largest tech fund is estimated to have lost about $18.6 billion on its public portfolio alone during the quarter that ended March 31, even greater than the record $18.3 billion drop marked in the fiscal second quarter, according to Kirk Boodry, an analyst at Redex Research who publishes on SmartKarma. That would mean a loss for the Vision Fund unit of about $10 billion, accounting for SoftBank’s stake in each fund, Boodry estimates.

It’s a drastic reversal from a year ago when Son took the stage in Tokyo to announce SoftBank had earned more money in a single quarter than any Japanese company in history. The company he founded about 40 years earlier hit net profit of ¥1.93 trillion ($17.7 billion at the time), eclipsing Japan Inc. heavyweights such as Toyota Motor Corp. and NTT Corp.