Previous gig: Marsico conceived the focused investing style behind the wildly successful Janus Twenty (JAVLX). By the time he left in 1997, the young fund manager was running more than $10 billion for the firm.
Why he split: According to news accounts at the time, Marsico quit after Janus founder and CEO Thomas Bailey rejected his bid to take over the company.
Today: Marsico stuck around Denver and launched his own firm, Marsico Capital Management, in 1997. The firm It now has more than $55 billion in assets and 74 employees. Marsico's $2.1 billion flagship fund -- Marsico Focus (MFOCX) -- has lost 3.4% annually since 2007.
NEXT: Chuck de Lardemelle and Charles de Vaulx