Estimated net worth: $67 billionAmount pledged: $25 millionZuckerberg's philanthropy organization The Chan Zuckerberg Initiative announced in March it was donating $25 million towards the Therapeutics Accelerator set up by the Gates Foundation, Wellcome, and Mastercard. This makes up just under 0.04% of Zuckerberg's estimated net worth.Following the donation a TikTok video illustrating how little of Zuckerberg's wealth $25 million makes up went viral.Estimated net worth: $103 billionAmount pledged: $250 millionGates' philanthropic organisation The Bill and Melinda Gates foundation initially pledged $100 million towards fighting the pandemic in February.In March, the Gates Foundation said it would contribute $50 million towards a joint fund with Wellcome and Mastercard called the COVID-19 Therapeutics Accelerator, which combined would hold a $125 million pot. It is not clear whether that $50 million came out of the initial $100 million pledge or not.On April 15 the Gates foundation announced it was pledging a further $150 million, days after President Donald Trump said he was withdrawing funding to the World Health Organization — a move Bill Gates openly criticized.The total sum of $250 million constitutes 0.24% of Bill Gates' $103 billion net worth.The foundation is also funding at-home coronavirus tests in Washington State, and Gates says it will help fund the construction of seven factories to manufacture potential candidates for a vaccine, even though at most one vaccine candidate would be selected.Estimated net worth: $140 billionAmount pledged: $100 millionJeff Bezos announced in early April he was donating $100 million to Feeding America, a nonprofit focused on supporting food banks.At time of writing Jeff Bezos is the world's richest person with an estimated $123 billion, meaning $100 million would make up roughly 0.08% of his fortune.Even in ordinary times, food insecurity in American households is an important problem, and unfortunately COVID-19 is amplifying that stress significantly, Bezos wrote in an Instagram post.Meanwhile, Bezos' company Amazon has set up its own relief fund for its contractors and seasonal workers, kicking in an initial $25 million and opening the fund up to outside donations.Jeff Bezos is one of the few billionaires who has seen his wealth increase alongside the coronavirus pandemic. At time of writing Bezos' net worth has increased by almost $25 billion since the beginning of 2020.Estimated net worth: $3.89 billionAmount pledged: $1 billionThe Twitter CEO announced on April 7 he was donating $1 billion in equity from his digital payments company Square to a relief fund called Start Small. Dorsey said it will initially focus on coronavirus relief, but will in time move towards funding girls' health and education.Dorsey published a link to flow tracker with the fund. At time of writing, it shows $100,000 is earmarked for America's Food Fund.According to Dorsey, the fund constitutes roughly 28% of his net worth.San Francisco Chronicle reporter Owen Thomas wrote this isn't the first incarnation of the Start Small fund. He points out that Dorsey made a promise in a 2015 SEC filing for Square that he would donate millions of shares into the Small Start fund, but that as of 2018 they had not materialized in the public record.Thomas also points out that, as an LLC fund, the money is not yet committed, and can return to Dorsey at any point.