4. Lawrence Ellison
Company: Oracle
Larry is the co-founder and CEO of Oracle Corporation, one of the world's leading enterprise software companies. Larry left the University of Illinois at Urbana-Champaign at the end of his second year, after not taking his final exams because his adoptive mother had just died. “I have had all the disadvantages required for success,” Larry said once. As of 2015, Forbes estimates Larry's wealth at $54.3 billion.