This Citadel aspires not to turn boys into men, but to turn cash into, well, more cash. Citadel Investment Group, whose seeds were planted in super-trader Ken Griffin's Harvard dorm room in 1987, has become one of the world's largest hedge funds, accounting for around 8% of trading activity at the New York Stock Exchange and Nasdaq every day. Because of this high volume, the company also acts as a market maker for equity options and for some blue-chip stocks on smaller exchanges. It manages some $11 billion of assets for institutional and high-net-worth investors, as well as its own account.