James Simons

Lifetime donations: $1.2 billion
Net worth: $12.3 billion
Generosity Index: 10%
James Simons is chairman of investment-management company Renaissance Technologies, one of the largest and most successful hedge fund companies in the world with $65 billion in assets. Simons served as the company's CEO until retiring in 2009.
Twenty-one years ago, Simons and his wife Marilyn established the Simons Foundation, which primarily supports educational causes. Since then, the couple has founded two additional organizations in memory of their two sons who died in 1996 and 2003: The Paul Simons Foundation gives to social and educational causes, and the Nick Simons Foundation trains rural healthcare workers in Nepal and gives to humanitarian and social causes.
Simons has also donated $30 million to autism research and has pledged to donate $100 million more.
Source: Wealth-X