SoftBank Group Corp.’s founder Masayoshi Son said he has $80 billion (Y8.3 trillion) in cash to buy back more shares and continue investing in both private and public companies.

"If our shares drop down, I will buy back more shares more aggressively,” the chief executive officer said at the New York Times DealBook conference Tuesday. "We have $80 billion in cash at hand.”

After a record fall in its share price in March, SoftBank unveiled plans to offload ¥4.5 trillion in assets and buy back ¥2.5 trillion of its own stock. The idea of going private through a buyout has been discussed within SoftBank for at least five years, but Son declined to comment on whether he would take his company off the stock market.

Son also defended his recent investment in public equities. SoftBank has poured about $20 billion into tech stocks and derivatives through a unit in which the billionaire personally holds a one-third stake. A ¥292 billion derivative loss in the September quarter helped all but wipe out gains it made in the first quarter.

"Who said I should not invest in public companies if I believe they will become successful companies in the AI revolution?” he said.