Twitter chief executive Jack Dorsey has pledged $1 billion of his stake in Square, the payments processor that he co-founded and heads, to help fund relief efforts related to the coronavirus pandemic. 

The amount represents about 28% of his wealth.

He said the money will be donated to his charity fund, Start Small, which would later focus its attention to universal basic income and girls' health and education. 

Jack Dorsey, who for years has kept details of his charitable efforts private, said all donations to and from the fund would now be visible to the public at all times through a public document.

Dorsey, whose net worth is estimated at $3.3 billion by Forbes, also said that he was pledging his stake in Square instead of Twitter because he owns a bigger portion of the payments processor. 

He also said that he would pace the sale of the pledged shares over time.

The US has so far recorded more than 380,000 coronavirus cases, with the total death toll rising to over 12,300.