The SpaceX founder and CEO is now worth more than $185 billion, thanks in large part to the ongoing surge in the stock price of his electric-car company, Tesla, according to media reports. Bezos, who runs Amazon.com as well as the spaceflight outfit Blue Origin, is currently worth $184 billion, according to CNBC.
Bezos had held the world's-richest title since 2017.
Musk began 2020 worth $27 billion, then padded his pocketbook in historic fashion during the year, CNBC reported.
"Musk's wealth surge over the past year marks the fastest rise to the top of the rich list in history — and is a dramatic financial turnaround for the famed entrepreneur, who just 18 months ago was in the headlines for Tesla's rapid cash burn and his personal leverage against the company's stock," CNBC wrote. "Tesla's rocketing share price — which has increased more than ninefold over the past year — along with his generous pay package have added more than $150 billion to his net worth."
SpaceX — which, unlike Tesla, isn't a publicly traded company — had a big 2020 as well. For example, SpaceX launched two crewed missions to the International Space Station last year, the first orbital human spaceflights to lift off from the U.S. since NASA retired its space shuttle fleet in 2011.
All told, SpaceX launched 26 missions in 2020, the most it has ever lofted in a calendar year. The company also made big strides in the development of Starship, the transportation system it's developing to take people to the moon, Mars and beyond.
Musk has long said that he founded SpaceX back in 2002 primarily to help humanity colonize Mars — and that he plans to devote a large chunk of his growing wealth to help make this happen.
"About half my money is intended to help problems on Earth and half to help establish a self-sustaining city on Mars to ensure continuation of life (of all species) in case Earth gets hit by a meteor like the dinosaurs or WW3 happens and we destroy ourselves," Musk wrote in a 2018 tweet, which he recently pinned to the top of his Twitter account.
Bezos also wants to help humanity extend its footprint into the final frontier.
"Blue Origin believes that in order to preserve Earth, our home, for our grandchildren's grandchildren, we must go to space to tap its unlimited resources and energy," the company's mission statement reads, in part. "Like the Industrial Revolution gave way to trade, economic abundance, new communities and high-speed transportation — our road to space opens to the door to the infinite and yet unimaginable future generations might enjoy."
Musk and Bezos both stress that reusable spaceflight systems are key to achieving such grand ambitions. The two billionaires have traded jabs about each other's systems and reusability milestones in the past, so any competitive feelings evoked by Musk's ascension to the billionaire top spot would not be entirely new.
Mike Wall is the author of "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.