23. JameS SimonS
$20 billion Self-made Score: * Source: hedge Funds age: 80 reSidence: east setauket, ny PhilanthroPy score: Simons’ Renaissance Technologies keeps raising huge sums of money: The quantitative-trading hedge fund firm now manages $57 billion. But clients piling into Renaissance are unable to get into its legendary $10 billion Medallion fund, which only trades capital belonging to Simons and Renaissance employees and owners. Simons, who founded Renaissance in 1982, officially retired from daily operations 9 years ago but remains its chairman and benefits from its funds. He has given away more than $2 billion to charity. His foundation is the primary funder of Math for America’s $225 millionplus fellowship program for public school math and science teachers.