follow the money
en.wikipedia.org/wiki/The_Giving_Pledge
In June 2010, the Giving Pledge campaign was formally announced and Bill Gates and Warren Buffett began recruiting members. As of August 2010, the aggregate wealth of the first 40 pledgers was $125 billion. As of April 2011, 69 billionaires had joined the campaign and given a pledge, and by the following year, The Huffington Post reported that a total of 81 billionaires had committed.
As of 2012, signatories of the pledge included: Hasso Plattner, David Rockefeller, Azim Premji, Richard Branson, Elon Musk, Tim Cook, Sara Blakely, and Kiran Mazumdar-Shaw. By May 2017, 158 individuals and/or couples were listed as pledgers.
The organization's goal is to inspire the wealthy people of the world to give at least half of their net worth to philanthropy, either during their lifetime or upon their death. The pledge is a moral commitment to give, not a legal contract. On The Giving Pledge's website, each individual or couple writes a letter explaining why they chose to give.
Name Net worth $ billions
Bill and Melinda Gates 77.3
Warren Buffett 66.7
Larry Ellison 49.3
Michael Bloomberg 37.2
Mark Zuckerberg 35.7
Carl Icahn 21.3
Azim Premji 17.5
Paul Allen 17.4
Ray and Barbara Dalio 15.6
James + Marilyn Simons 15.5
Elon Musk 15.2
Ronald Perelman 14.5
Vladimir Potanin 13.5
Patrick Soon-Shiong 13
H+S Simmons 10
and many more