Elon Musk sold another US$3.58 billion worth of Tesla Inc. shares, bringing the total amount he’s offloaded since late last year to almost US$40 billion.

The latest disposal of about 22 million shares this week coincided with Musk falling from the top spot on the Bloomberg Billionaires Index, a position he’d occupied since September of last year. Tesla’s market value also slumped below the half-trillion-dollar mark for the first time since November 2020.

Musk’s persistent selling after repeated assurances that he was done unloading Tesla stock reflects mounting pressure on the finances of Twitter Inc. His erratic and impulsive approach to running the social-media company has alienated advertisers, and efforts to bring in more revenue from subscription fees backfired when impostor accounts exploited a poorly executed rollout of verification badges.

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The chaos at Twitter has been an overhang on Tesla, which is facing its own set of challenges. The electric-car maker has cut prices and production this quarter in China and taken the rare step of offering incentives in the U.S. Musk has said the company is struggling to cope with the effects that China’s slumping property market, Europe’s energy crisis and the Federal Reserve’s interest rate increases are having on demand.

Tesla shares rose 0.6 per cent to US$157.67 as of 11:13 a.m. Thursday in New York. The stock has plunged 55 per cent this year.

Musk tried for months to get out of the Twitter deal but ultimately failed. To help finance the purchase, he offloaded more than US$15 billion of Tesla shares before closing the transaction — about US$8.5 billion in April, then US$6.9 billion in August. In November, he sold another US$3.95 billion of his holdings.

Musk layered a significant amount of high-interest debt on Twitter’s balance sheet as part of his buyout. The company’s debt load swelled to about US$13 billion — up from US$1.7 billion pre-deal — and it’s now facing annual interest payments approaching US$1.2 billion. Its borrowing could get even more expensive because the interest rates on about half of that debt aren’t locked in and will rise with the market.

“At risk of stating obvious, beware of debt in turbulent macroeconomic conditions, especially when Fed keeps raising rates,” Musk tweeted this week.

Musk’s recent sales shrink his stake in the company to roughly 13 per cent, according to Bloomberg data. As of Wednesday’s close, he was worth US$160.9 billion, ranking No. 2 on the Bloomberg Billionaires Index after France’s Bernard Arnault. His fortune has dropped by US$109.4 billion this year.

Musk’s remaining stake in Tesla — roughly US$94 billion — still makes up almost 60 per cent of his total net worth, according to the index. Around US$57 billion of that is shares he owns outright, and the remainder is vested stock options he’s received from a 2018 mega grant.