Michael Bloomberg

As a three-term Mayor of New York City, Michael Bloomberg has done what many American billionaires have not, run for public office successfully and repeatedly. He has a net worth of $35.5 billion as of March 2015. An MBA-holder from the Harvard School of Business, Bloomberg earned his place on the List of Billionaires as the founder, CEO and 88% owner of Innovative Market Systems in 1981, which was renamed Bloomberg L.P. in 1987.

The Bloomberg L.P. began as a way of distributing terminals with software that had up-to-the-minute business news to paying clients, the first of these being Merrill Lynch. Bloomberg L.P. has expanded to include Bloomberg News, radio stations and other products.

As mayor of New York City, Bloomberg entered office only a few months after the September 11, 2001 terrorist attacks in the city. He received the support of the outgoing mayor, Rudolph Giuliani, and went on to change the city’s election laws, allowing for his third consecutive term in office. He left office on the first day of 2014.