Jeff Greene and Mary Callahan Erdoes at the World Economic Forum, 2015
Jeff Greene joined the billionaire’s club in the 2000s by betting the subprime mortgage market would collapse. He made a 1,400% return over about 18 months in 2006 and 2007 through credit default swaps, widely considered to be among the causes of the housing market collapse of 2008, and ultimately of the Great Recession.
He now owns five massive personal homes and a 145-foot yacht. He started investing in real estate while at Harvard Business School, first buying a three-unit building and owning 18 properties by the time he earned his MBA. — Scott Klocksin