Elon Musk has become the wealthiest person on the planet.

Elon Musk has become the wealthiest person on the planet, surpassing Amazon CEO Jeff Bezos, thanks to the continued rise in Tesla’s stock price. Musk is now worth around $188 billion, according to Bloomberg’s Billionaires Index.

“How strange,” Musk tweeted Thursday. “Well, back to work …”

Musk eclipsing Bezos’ own extravagant personal wealth of around $187 billion marks the latest development in a years-long rivalry between the two tech magnates — one that often centers on the accomplishments of their respective businesses.

Bezos was reportedly so envious of Musk’s success in securing a $1.3 billion incentive package for Tesla’s Gigafactory in Nevada that it served as the genesis for Amazon’s beauty pageant-style search for its second headquarters. Bezos has a spaceflight company in Blue Origin much like Musk does with SpaceX. The two men have traded barbs about their rockets and even fought over hallowed NASA real estate. (SpaceX won that fight and is the only of the two companies to successfully reach orbit.)

Musk only just passed Bill Gates in November to become the second-richest person in the world. The Tesla CEO saw his personal wealth skyrocket in 2020 to the tune of more than $150 billion, in large part because Musk owns a lot of Tesla stock — about 20 percent of the company, in fact. And Tesla’s stock has grown incredibly valuable over the last year or so, too, as Musk pulled the company out of so-called “production hell” and dramatically increased sales of its electric vehicles, thanks to the more affordable Model 3 sedan and Model Y SUV. That coincided with an incredible rise of retail investors who were more willing to fully buy into Tesla’s story than many on Wall Street once were.

The billionaire CEO’s stock stash continues to grow, especially after he signed a major 10-year compensation package with the company in 2018 that further tied his earnings to Tesla’s stock price and revenue goals. He is awarded a raft of company stock options every time a new milestone is hit; the first tranche, which he received earlier this year, was worth some $800 million.

Like most billionaires, Musk has only seen his overall wealth increase during the coronavirus pandemic. But unlike that peer group, Musk claimed in court to be “cash poor” and “financially illiquid” in 2019 and said last year that he would sell “almost all physical possessions,” including his mansions. He takes loans against the stock that makes him so wealthy and plows that money back into his companies, like when he dumped around $100 million into The Boring Company in 2018. Musk has a long history of using his own personal wealth to fund new endeavors, too, as he funded Tesla and SpaceX after becoming a millionaire running Zip2 and PayPal.

Musk may now be the richest man on Earth by the standards of money-focused outlets like Bloomberg and Forbes, though they tend to focus on calculating knowable assets. However, authoritarian leaders like Vladimir Putin and Mohammed bin Salman are both extremely personally wealthy in ways that are harder to calculate and also have unchallengeable access to the vast wealth of their nations.