Jack Dorsey plans to donate US$1 billion ($1.63 billion) to fight the coronavirus outbreak, funds that will drive research to help “disarm this pandemic”.

The Twitter CEO’s pledge is by far the largest gift by a private individual yet during the pandemic.

Mr Dorsey, 43, who co-founded Twitter in 2006 and went on to found payments company Square, tweeted on Tuesday that he was donating $1bn of Square shares to a charitable fund called Start Small, to “fund global COVID-19 relief”.

I’m moving $1B of my Square equity (~28% of my wealth) to #startsmall LLC to fund global COVID-19 relief. After we disarm this pandemic, the focus will shift to girl’s health and education, and UBI. It will operate transparently, all flows tracked here: https://t.co/hVkUczDQmz

— jack (@jack) April 7, 2020

The sum not only dwarfs contributions by other philanthropists; it represents a significant proportion of Mr Dorsey’s fortune.

He said the donation was equivalent to about “28% of my wealth”.

Mr Dorsey has amassed riches of about US$3.9 billion ($6.35 billion), according to the Bloomberg Billionaires Index.

Jeff Bezos, the founder of Amazon and the world’s richest person, has said he will donate US$100 million ($163 million) to food bank charity Feeding America to help relief efforts during the pandemic.

“Even in ordinary times, food insecurity in American households is an important problem, and unfortunately COVID-19 is amplifying that stress significantly,” Mr Bezos, 56, said in an Instagram post last week.

Mr Bezos’ donation represents less than 0.1% of his estimated US$123 billion ($200 billion) fortune.

The Bill & Melinda Gates Foundation has given US$100 million ($163 million) to efforts to develop a COVID-19 vaccine and to fund testing and treatments.

Facebook founder Mark Zuckerberg has offered more than US$25 million ($40.7 million) to help research through the Bill & Melinda Gates Foundation.

Michael Dell, the founder of Dell computers, has committed $100 million ($163 million).

Mr Dorsey says all of the gift’s donations will be tracked through a public Google Sheet. That document shows $100,000 has been given so far to America’s Food Fund, an organisation co-founded by Laurene Powell Jobs and Leonardo DiCaprio.

After the coronavirus outbreak has been contained, Start Small will shift its focus to funding girls’ health and education, as well as universal basic income, a regular cash payment made to citizens by the government, Mr Dorsey said.

“Why UBI and girl’s health and education? I believe they represent the best long-term solutions to the existential problems facing the world,” Mr Dorsey wrote in a follow-up tweet.

“UBI is a great idea needing experimentation. Girl’s health and education is critical to balance.”

“I hope this inspires others to do something similar,” Mr Dorsey said of his contribution.

“Life is too short, so let’s do everything we can today to help people now.”