Opportunistic leader of chicago hedge fund outfit Citadel recently bought up battered portfolios from distressed funds Sowood and Amaranth. Also gave troubled online brokerage E-Trade a $2.6 billion boost. Founded Citadel with $4.6 million 1990. Today firm manages $20 billion. Last year flagship Kensington fund returned 32% net of fees. Bought Jasper Johns painting "False Start" for $80 million in 2006.