CEO of securities firm Bear Stearns from 1978-1993. Bear Stearns collapsed in 2008, and was bought that March by JPMorgan Chase. Greenberg - who signed with JPMorgan as vice chairman emeritus, and 40% of trading commissions he generated - claimed Bear Stearns failed due to "a groundless rumor" it had liquidity problems, and his successor's ignoring Greenberg's warnings that the firm was over-leveraged.