How did Bloomberg make his money?

Since entering the presidential race in November, Mike Bloomberg has spent more than $400 million of his own fortune on campaign advertisements — a mere fraction of his total net worth.

The Republican-turned-Democrat, worth a staggering $63.7 billion, is the eighth richest person in the world, according to Forbes. He is the wealthiest person to ever run for president.

Bloomberg, who grew up in a middle-class, Massachusetts family, according to his website, graduated from Johns Hopkins University in 1964 with an electrical engineering degree. He then earned his MBA from Harvard and went to work on Wall Street.

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Starting in June 1966, Bloomberg snagged his first post-grad school job at Salomon Brothers, the Wall Street investment bank, where he counted securities by hand and earned $9,000 a year. He eventually worked his way up the ranks, and in 1972, was named partner.

In 1979, Bloomberg was demoted, shifting off the trading floor to overseeing information systems. Over the next two years, he educated himself about early computers, beginning to form the idea of Bloomberg Terminal. Bloomberg was fired in 1981 after Salomon was acquired by Phibro.

As partner, Bloomberg voted to accept the acquisition bid after realizing he’d receive a $10 million cash payout, which he used to launch his own company. Initially named Innovative Market Systems, which was designed to make it easier for traders to analyze data, he changed the name in 1986 to Bloomberg LP.

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According to Business Insider, Bloomberg LP eventually debuted the Bloomberg Terminal, the computer software that helps traders wade through data. Merrill Lynch was the first customer, purchasing 22 of them and investing $30 million in the company for a 30 percent stake.

Through the 1980s, Bloomberg LP became widely successful: By 1989, it was worth $2 billion. The company then ventured into new areas, launching Bloomberg News and Bloomberg TV.

In 2001, Bloomberg announced that he was running for New York City mayor: He was elected shortly after the Sept. 11 attacks, and went on to serve through 2013. Already a billionaire, he accepted a salary of $1 per year. (While in office, he recused himself from day-to-day operations at Bloomberg LP but reserved the right to weigh in on longer, strategic decisions).

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In 2015, he stepped back into his role as Bloomberg LP CEO after serving a two-year stint as a full-time philanthropist.

Bloomberg also has a number of multimillion-dollar properties across the world, including Colorado, London, Bermuda and multiple in New York.

He currently owns about 88 percent of Bloomberg LP, according to Forbes, which is worth a reported $10 billion. Over his lifetime, he’s donated roughly $8 billion to charity, or 13 percent of his total net worth.