DETROIT, MI - OCTOBER 29:  Michael Bloomberg, billionaire and former Mayor of New York City, speaks at CityLab Detroit, a global city summit, on October 29, 2018 in Detroit, Michigan. Bloomberg is considered to be a potential Democratic presidential candidate for the 2020 election. (Photo by Bill Pugliano/Getty Images)
Bill Pugliano/Getty Images
DETROIT, MI - OCTOBER 29: Michael Bloomberg, billionaire and former Mayor of New York City, speaks at CityLab Detroit, a global city summit, on October 29, 2018 in Detroit, Michigan. Bloomberg is considered to be a potential Democratic presidential candidate for the 2020 election. (Photo by Bill Pugliano/Getty Images)
Now playing
02:24
Michael Bloomberg mulls presidential run
CNN
Now playing
03:06
Hear doctor's message for people with J&J vaccine concerns
Barbers from King's Cutz give haircuts indoors while observing COVID-19 safety restrictions on March 13, 2021 in Los Angeles, California.
Mario Tama/Getty Images
Barbers from King's Cutz give haircuts indoors while observing COVID-19 safety restrictions on March 13, 2021 in Los Angeles, California.
Now playing
01:43
US consumer prices increased in March
Now playing
01:27
See the first community of 3D-printed homes
Now playing
04:22
Levi's CEO has message for Mitch McConnell
Elon Musk's Neuralink says this monkey is playing Pong with its mind
From Neuralink/Youtube
Elon Musk's Neuralink says this monkey is playing Pong with its mind
Now playing
01:41
Elon Musk's company says this monkey is playing Pong with his mind
CNN
Now playing
02:36
The truth behind Covid-19 vaccines for sale on the dark web
Heinz ketchup packets are shown in New York on Monday, August 22, 2005. H.J. Heinz Co., the world's biggest ketchup maker, said first-quarter profit fell 19 percent on expenses to cut jobs and sell businesses.  (Photo by Andrew Harrer/Bloomberg via Getty Images)
Andrew Harrer/Bloomberg/Getty Images
Heinz ketchup packets are shown in New York on Monday, August 22, 2005. H.J. Heinz Co., the world's biggest ketchup maker, said first-quarter profit fell 19 percent on expenses to cut jobs and sell businesses. (Photo by Andrew Harrer/Bloomberg via Getty Images)
Now playing
01:53
Restaurants face a nationwide ketchup packet shortage
CNN
Now playing
03:53
Norwegian Cruise Line CEO to CDC: We want to be treated fairly
Getty Images
Now playing
02:18
This airplane-shaped bag is selling for more than some actual planes
A medical worker prepares to administer a dose of the AstraZeneca vaccine in Belgrade, Serbia, Tuesday, March 23, 2021. American federal health officials say results from a U.S. trial of AstraZeneca's COVID-19 vaccine may have included "outdated information" and that could mean the company provided an incomplete view of efficacy data. (AP Photo/Darko Vojinovic)
Darko Vojinovic/AP
A medical worker prepares to administer a dose of the AstraZeneca vaccine in Belgrade, Serbia, Tuesday, March 23, 2021. American federal health officials say results from a U.S. trial of AstraZeneca's COVID-19 vaccine may have included "outdated information" and that could mean the company provided an incomplete view of efficacy data. (AP Photo/Darko Vojinovic)
Now playing
03:46
These are all the complications AstraZeneca's vaccine has faced
A driver rides his car in front of the Lyft Drivers Hub in Los Angeles, California, March 29, 2019. Ride-hailing company Lyft made its Initial Public Offering (IPO) on the Nasdaq Stock Market on March 29th. (Photo by Apu Gomes/AFP/Getty Images)
Apu Gomes/AFP/Getty Images
A driver rides his car in front of the Lyft Drivers Hub in Los Angeles, California, March 29, 2019. Ride-hailing company Lyft made its Initial Public Offering (IPO) on the Nasdaq Stock Market on March 29th. (Photo by Apu Gomes/AFP/Getty Images)
Now playing
04:55
Lyft co-founder: Supporting voter access is important for business
Citigroup Chairman Richard Parsons delivers remarks on the US economy at the New York State Bar Association meetings in New York, January 28, 2009. Troubled US banking giant Citigroup last week named Parsons as its new chairman, the longtime top executive at media giant Time Warner, to steer it through its most challenging period.  AFP PHOTO / Emmanuel Dunand (Photo credit should read EMMANUEL DUNAND/AFP via Getty Images)
EMMANUEL DUNAND/AFP/AFP via Getty Images
Citigroup Chairman Richard Parsons delivers remarks on the US economy at the New York State Bar Association meetings in New York, January 28, 2009. Troubled US banking giant Citigroup last week named Parsons as its new chairman, the longtime top executive at media giant Time Warner, to steer it through its most challenging period. AFP PHOTO / Emmanuel Dunand (Photo credit should read EMMANUEL DUNAND/AFP via Getty Images)
Now playing
02:47
Dick Parsons: Georgia law is a bald-faced attempt to suppress Black vote
Resturant Yurkevcih Pkg 1
CNN
Resturant Yurkevcih Pkg 1
Now playing
02:55
Restaurants are still struggling, but see hope on the horizon
WASHINGTON, DC - SEPTEMBER 16:  Patrick Soon-Shiong, chairman and CEO of the Institute for Advanced Health, participates in a discussion at the Bipartisan Policy Center, September 16, 2014 in Washington, DC.  The Bipartisan Policy Center released a report titled Innovative Strategies from America's Business Leaders.  (Photo by Mark Wilson/Getty Images)
Mark Wilson/Getty Images North America/Getty Images
WASHINGTON, DC - SEPTEMBER 16: Patrick Soon-Shiong, chairman and CEO of the Institute for Advanced Health, participates in a discussion at the Bipartisan Policy Center, September 16, 2014 in Washington, DC. The Bipartisan Policy Center released a report titled Innovative Strategies from America's Business Leaders. (Photo by Mark Wilson/Getty Images)
Now playing
04:04
Patrick Soon-Shiong: We have to recognize racism and 'break it'
Now playing
05:41
NFTs have completely transformed these digital artists' lives
(CNN) —  

Entrepreneur and philanthropist-turned politician Michael Bloomberg has been called one of most successful New York mayors in the city’s history.

Now the 77-year-old media mogul apparently wants to be president, too. He is preparing to file paperwork in Alabama to qualify for that state’s presidential primary. He has one big supporter already–fellow billionaire businessman Leon Cooperman, an outspoken critic of leading Democratic candidate Elizabeth Warren.

Bloomberg is wealthy enough to fund his own campaign. Forbes estimates his current net worth at $52.4 billion–an amount that dwarfs not only the value of President Donald Trump’s real estate empire, but also the fortunes of fellow media moguls Rupert Murdoch, Ted Turner, and Sumner Redstone combined.

Just how did Bloomberg, a Boston native and son of an accountant and a secretary, amass his fortune?

Wall Street as we know it today wouldn’t exist without his innovations. After earning his MBA from Harvard Business School in 1966, he got a job counting securities by hand in the “The Cage” at the former New York investment bank known as Salomon Brothers.

Bloomberg became a Wall Street star at the firm, whose leaders later convinced him to manage the company’s fledgling computer systems unit in 1979.

A picture of former New York mayor Michael Bloomberg, left, and John Gutfreund of Salomon Brothers in New York in 1975.
Edward Hausner/The New York Times/Redux
A picture of former New York mayor Michael Bloomberg, left, and John Gutfreund of Salomon Brothers in New York in 1975.

Eventually Bloomberg worked his way up to general partner before being let go in 1981, when Salomon merged with commodities trading firm Phibro Corporation. He received a $10 million severance.

He used that money to begin building his financial media empire, co-founding Innovative Market Systems with Charles Zegar, Thomas Secunda, and Duncan MacMillan the same year.

“I didn’t sit around wondering what was happening at the old firm,” Bloomberg wrote in his 2001 autobiography “Bloomberg by Bloomberg”. “I didn’t go back and visit. I never look over my shoulder. Once finished: Gone. Life continues!”

The then-39-year-old used the financial know-how and information technology expertise he developed at Salomon to create the Bloomberg terminal in 1982, a software system with a specialized keyboard used by financial professionals to trade stocks electronically and access live market data.

Michael Bloomberg, founder and CEO of Bloomberg LP, poses for a portrait March 15, 1997 in his company's New York City offices.
Stan Godlewski/Hulton Archive/Getty Images
Michael Bloomberg, founder and CEO of Bloomberg LP, poses for a portrait March 15, 1997 in his company's New York City offices.

The apparatus revolutionized an analog Wall Street and became a ubiquitous tool used in investment banking, competing with Thomson Reuters Eikon, FactSet, and S&P Capital IQ.

Innovative Market Systems was renamed Bloomberg L.P. in 1986. In 1990, the company created its own news service before launching Bloomberg.com in 1993.

Not content with business success, Bloomberg ran for mayor of New York City in 2001, succeeding Rudolph Giuliani in the aftermath of 9/11. Bloomberg’s time as mayor was riddled with controversial policies such as stop-and-frisk policing, the rise of charter schools, and pressuring the city council to temporarily change the rules on term limits so he could run for a third term.

But New York City’s overall quality of life improved under Bloomberg’s tenure. Crime rates dropped. Graduation rates at city schools rose. So did city revenues and Bloomberg’s own net worth.

Bloomberg L.P.’s terminal user base has more than doubled, to 325,000 subscribers currently from 160,000 in 2001, according to the company.

With a price point of $24,000 per subscriber for its terminals, the privately-held company’s annual revenue eclipsed $10 billion in 2018, according to an analyst estimate.

In March, Forbes ranked Bloomberg as the ninth richest person in the world and the wealthiest media mogul on the planet.