• Tesla and SpaceX CEO Elon Musk invested early in many innovative companies 
  • Bernard Arnault is the chairman and CEO of LVMH Moët, Hennessy – Louis Vuitton
  • Bill Gates, who co-founded Microsoft, started his road to riches when he was 13

Technology, e-commerce, construction, luxury goods and commodities — are some of the industries behind the wealth of the richest people in the world. Their journey to becoming billionaires includes making investment after investment. In other words, making money make more money.

Look back at how the richest people in the world got their start, how they became billionaires and how much they are currently worth.

Elon Musk

Tesla CEO Elon Musk attends the Tesla Shanghai Gigafactory groundbreaking ceremony in Shanghai

The CEO of Tesla has a net worth of $273.9B, according to Forbes' real-time ranking of billionaires. As of Sept. 13, his real-time net worth was up by $3.2B.

Though famously known for Tesla and SpaceX, Elon Musk was an early investor in some of the most innovative companies today. He started the company Zip2 along with his brother Kimbal. Compaq Computer Corp. later bought Zip2. He used the money from the sale to create the venture, which later merged with Confinity to create PayPal. PayPal was bought by eBay for $1.5B.

Elon's 11.7% share in PayPal amounted to $180M after taxes. He then invested it in various ventures, including $100M to SpaceX, $70M to Tesla and $10M to SolarCity. Today, part of the 51-year-old billionaire's wealth comes from the tunneling startup, the Boring Company, and Neuralink.

Bernard Arnault

As Amazon stocks plummeted, a French fashion Bernard Arnault mogul surpassed Bezos as the richest man in the world. Creative Commons

The second-richest person in the world is the chairman and CEO of LVMH Moët, Hennessy – Louis Vuitton, the world's largest luxury goods company. In Forbes' real-time list, the current net worth of Arnault and his family is $160.2B. LVMH is behind brands such as Louis Vuitton, Fendi, Givenchy, Guerlain, Marc Jacobs and Sephora, along with Tiffany & Co, which it acquired in January 2021.

Arnault's wealth came from construction. He convinced his father, Jean Leon Arnault, to disband the construction division of his civil engineering firm and expand into more profitable businesses. Arnault then used the money to invest in real estate. The family relocated to America in 1981, branching out their real estate investments in the process.

When Arnault returned to France in 1983, he expanded to the textile industry. In cooperation with Antoine Bernheim, a managing partner from Lazard Fréres, Arnault bought the newly bankrupt firm Boussac Saint-Frères. He sold most of the shares, only keeping the Christian Dior brand and the department store Le Bon Marché. He became the CEO of Dior in 1985.

According to Forbes, LVMH's performance was "pandemic-defying" after seeing a jump in sales from March 2020 to May 2021. Today, LVMH's empire includes 70 fashion and cosmetics brands. Luxury brands such as Tiffany & Co. and Dior also invest in brand ambassadors to further expand their market reach.

Jeff Bezos

Jeff Bezos built one of the world's most successful global companies from his garage-based startup
Jeff Bezos built one of the world's most successful global companies from his garage-based startup AFP / Jim WATSON

The chairman and founder of Amazon is worth $159.8B, according to Forces' real-time rankings, placing Jeff Bezos third among the richest people in the world.

Bezos' wealth predominantly came from the e-commerce giant he founded in 1994 out of his garage in Seattle. His wealth comes from a series of investments and acquisitions through the years. He invested $112M in AirBnb, $1M in Google in 1998 and $37M in Uber in 2011, to name a few. His investment company Bezos Expeditions also invests in healthcare and wellness companies, investing $56 million in Juno Therapeutics in 2014, $100M in Grail in 2016 and $15M in Mindstrong Health in 2018. The 58-year-old self-made billionaire also owns The Washington Post and Blue Origin.

Bezos also acquired Elemental Tech in 2017, rebranded into Amazon Web Services (AWS) Elemental; IMDb, Kiva Systems (now Amazon Robotics) in 2012, in 2017, Zappos in 2009, and Whole Foods for $13.2B.

In 2021, he topped the list of Forbes 400 with a net worth of $201B. He was the CEO of Amazon until July 2021, when he stepped down to become its executive chairman. He also sold $8.8B of his Amazon stock and gave some of his shares away.

Gautam Adani

Adani Group Chairman, Gautam Adani smile Adani Group Chairman, Gautam Adani smiles after addressing the media in Ahmedabad on July 21, 2009. Adani spoke about "Adani Power Limited IPO" which opens on July 28. SAM PANTHAKY/AFP via Getty Images

Fourth on Forbes' real-time list of richest people in the world is infrastructure tycoon Gautam Adani, with a net worth of $150.5B. His family controls Mundra Port, the largest port in India.

Adani dropped out of college to work in the diamond trade, eventually foraying into the world of global trade as an importer of polyvinyl chloride, or PVC, for his brother's plastic business. He set up Adani Enterprises in 1988 as the group's flagship company for the import and export of commodities.

After getting approval from the Gujarat government in 1994 to set up a harbor facility at Mundra Port, Adani built rail and road links to convert Mundra Port into a commercial port.

He became the country's biggest airport operator after acquiring a 74% stake in Mumbai International Airport in September 2020. He also owns Abbot Point, a coal mining project in Australia.

Adani's revenue comes from Adani Group's varied investments in infrastructure, commodities, real estate and power generation and transmission. In May 2022, he acquired Swiss giant Holcim's cement business in India. The acquisition reportedly cost $10.5B.

He plans to invest up to $70B in renewable energy projects, with a mission to be the world's largest producer of green energy.

Bill Gates

American billionaire Bill Gates is the co-founder of TerraPower
American billionaire Bill Gates is the co-founder of TerraPower POOL via AFP / Evan Vucci

The fifth-richest person in the world is Bill Gates, the man behind Microsoft. He co-founded the company with school friend Paul Allen in 1975.

Gates' road to riches started when he was 13. He recalled being a student at Lakeside Private School in Seattle, Washington. When his school bought a teletype, it sparked his love for computers, hacking and coding.

Gates and Allen created a computerized scheduling system for Lakeside Private School in exchange for more computer time. The duo also created a computerized traffic analysis system, Traf-o-Data, which they sold for $20,000 to the Washington State Highway Department.

Gates was studying at Harvard Law School, while Allen was enrolled in Washington State University during the early days of microcomputers. Gates reportedly called the maker of the microcomputer Altair 8800 to offer to write software for them. By 1975, they sold the programming software called BASIC to Altair 8800's creator MITS for $3,000 plus royalties.

That same year, they founded Microsoft, which retained the rights to the programming language they created. They sold this software to personal computer hardware makers, resulting in rapid growth for Microsoft. Three years after its creation, Microsoft's annual revenue topped $1M.

With a current net worth of $109.1B, Gates' revenue comes from his software firm and diversified holdings, including investments in zero-carbon energy, the Canadian National Railway and AutoNation. Gates is also one of the largest owners of farmland in America.