Elon Musk’s net worth plunged $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 (TSLA) fell 21% in New York trading -- the most ever -- on news of a partnership between competitors Nikola Corp. and General Motors Co., deepening a sell-off that began last week after it was snubbed for inclusion in the S&P 500 index.

The world’s wealthiest people have lately seen wild swings in their net worth as retail traders accelerate buying and selling in stocks. Amazon.com Inc’s Jeff Bezos lost $7.9 billion Tuesday, while Zhong Shanshan added more than $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% in its Hong Kong debut, pushing Shanshan’s fortune to $50.9 billion.

Musk’s loss and Shanshan’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 $2.2 billion -- tied to his moonshot compensation package.

Musk, who is now worth $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% rally in Tesla shares from January to the end of August.