Elon Musk, founder and chief engineer of SpaceX speaks at the 2020 Satellite Conference and Exhibition March 9, 2020 in Washington, DC. (PHOTO / BLOOMBERG)

Elon Musk’s net worth plunged US$16.3 billion Tuesday, the largest single-day wipeout in the history of the Bloomberg Billionaires Index, as the Tesla Inc. rout continued.

The electric-carmaker fell 21 percent in New York trading -- the most ever -- on news of a partnership between competitors Nikola Corp and General Motors Co, deepening a selloff that began last week after it was snubbed for inclusion in the S&P 500 Index.

The electric-carmaker fell 21 percent in New York trading -- the most ever -- on news of a partnership between competitors Nikola Corp and General Motors Co, deepening a selloff that began last week after it was snubbed for inclusion in the S&P 500 Index

ALSO READ: Musk calls Gates underwhelming after billionaire buys a Porsche

The world’s wealthiest people have seen wild swings in their net worths lately as retail traders accelerate buying and selling in stocks. Amazon.com Inc.’s Jeff Bezos lost US$7.9 billion Tuesday, while Zhong Shanshan added more than US$30 billion to his fortune -- making him the third-richest person in China -- after shares of the bottled-water company he founded surged following an initial public offering.

Shares of Nongfu Spring Co, whose red-capped bottles are sold across China everywhere from mom-and-pop snack stalls to high-end hotels, jumped 54 percent in its Hong Kong debut, pushing Zhong’s fortune to US$50.9 billion. After opening lower, the stock was up 3.5 percent as of 10:38 am local time on Wednesday.

READ MORE: Elon Musk is now richer than Zuckerberg after Tesla stock split

Musk’s loss and Zhong’s gain are the largest moves in the history of the Bloomberg index, excluding net worth revisions for divorce, redistribution and inheritances. Musk’s drop would have been even larger if he hadn’t collected his third tranche of options Tuesday -- now worth US$2.2 billion -- tied to his moonshot compensation package.

Musk, who is now worth US$82.3 billion, fell behind Bernard Arnault for fifth on the list of the world’s richest people. The Tesla chief executive officer briefly joined the rarefied centibillionaire club last month, thanks to his audacious pay package and a nearly 500 percent rally in Tesla shares from January to the end of August.