Current net worth: $53.2 billion (attributed to Slim and his family)Source of wealth: Telecommunications giant America MovilSlim, 80, and several of his family members control Latin America's largest telecommunications company, per Forbes. He has also invested in construction, consumer goods, and real-estate firms in Mexico, in addition to holding a stake in The New York Times, per Forbes.Current net worth: $63.3 billionSource of wealth: Zara parent InditexThe 84-year-old Spaniard began his career in textile manufacturing but went on to cofound fast-fashion retailer Zara with his late wife Rosalia Mera in 1975, Business Insider previously reported.Current net worth: $72.5 billionSource of wealth: Berkshire Hathaway conglomerateInvestor Warren Buffett made his fortune running conglomerate Berkshire Hathaway, per Forbes. The company owns fast food staple Dairy Queen and insurer Geico.Current net worth: $112.1 billionSource of wealth: Louis Vuitton owner LVMHFrench businessman Bernard Arnault, 71, is the richest person in the fashion industry, Business Insider previously reported. However, the pandemic temporarily reversed the luxury conglomerate CEO's fortunes, sending both LVMH's share price and Arnault's net worth into a free fall.Current net worths: $113.6 billion (Gates), $72.1 billion (Ballmer)Source of wealth: MicrosoftBill Gates, 64, founded software giant Microsoft with his high school friend Paul Allen in 1975, Business Insider previously reported. The company made Gates a billionaire in 1986, the year after it went public, according to CNBC.Ballmer became one of Microsoft's first employees after dropping out of Stanford Business School in 1980, Forbes reported. Ballmer's Microsoft stake also made him a billionaire. He spent 14 years as Microsoft's CEO after Gates stepped down from the top post, and now owns the Los Angeles Clippers, per Forbes.Current net worth: $72.4 billionSource of wealth: OracleLarry Ellison, now 75, cofounded software firm Oracle to produce and sell customer relationship management databases, per Forbes. A two-time college dropout, Ellison is now best known as an international playboy and tech titan, Business Insider previously reported.Current net worths: $67.5 billion (Brin), $69.3 billion (Page)Source of wealth: Google parent AlphabetLarry Page and Sergey Brin co-founded Google in 1998 while working towards their PhDs at Stanford, per Forbes. The pair went on to spend decades atop Google parent Alphabet — with Page as CEO and Brin as president — before stepping down in December 2019.Current net worth: $183.1 billionSource of wealth: AmazonJeff Bezos, 56, left his job at a New York City hedge fund to sell books on the internet in 1994. That company, called Amazon, became the world's largest retailer and made its CEO the world's richest man in the process.Current net worth: $87.9 billionSource of wealth: FacebookMark Zuckerberg, 35, founded the social network in his dorm room at Harvard, Business Insider previously reported. Zuckerberg's 15% stake in the company makes him the seventh-richest person on the planet according to Forbes, but the billionaire has said that he and wife Dr. Priscilla Chan plan to give most of their wealth away.