Michael Bloomberg vs. Jeff Bezos

In 2018, Bloomberg pledged $1.8 billion to Johns Hopkins University, his undergraduate alma mater, adding $1.5 billion he had already given the school. As a teenager, Bloomberg worked at an electronics company in Cambridge, Massachusetts.

Growing up, Bezos worked summers on his grandfather's ranch repairing Caterpillar tractors. Bezos met Google founders Larry Page and Sergey Brin in 1998 and managed to become one of the company's first angel investors, putting in an estimated $250,000.