19. Pierre Omidyar
Pierre Omidyar, the French-Iranian-American businessman is the co-founder and current chairman of eBay. In 1998, he started the Omidyar Foundation with his wife. The organization donates to several causes including entrepreneurship, food, technology and energy. In 2015, Omidyar reportedly donated $270 million worth of his eBay shares to undisclosed charity. So far, he has given away an estimated $1 billion dollars.
18. Michael Dell
The chairman and CEO of the computer manufacturer, Dell, likes to support education, social and human services, arts and culture, and community development causes. According to Wealth-X, his lifetime donations are estimated at $1.1 billion. His foundation pledged to donate $25 million to build a 211-bed hospital in Austin, Texas.