The donation was worth US$5.74 billion, based on the closing prices of Tesla shares on the five days that he donated the stocks.

The filing did not disclose the name of the charity.

Late last year, the billionaire sold US$16.4 billion worth of shares after polling Twitter users about offloading 10% of his stake in the electric-car maker.

He suggested that he needed to sell some of the stocks, regardless of the Twitter poll, to pay taxes associated with his exercise of options due to expire this year.

He said last year that he will pay more than US$11 billion in taxes in 2021.

Experts have said there would be a tax benefit for Musk potentially gifting Tesla stock.

This is because shares that are donated to charity are not subject to capital gains tax, as they would be if they were sold.

In 2001, he set up the Musk Foundation, offering grants for the “development of safe artificial intelligence to benefit humanity” among other causes, according to its website. Musk’s foundation has over US$200 million in assets.

Musk has also flirted with more ambitious philanthropy goals. He tweeted last year that “if (the United Nations World Food Programme) can describe … exactly how US$6 billion will solve world hunger, I will sell Tesla stock right now and do it”.

Musk was responding to a plea for a donation from David Beasley, the World Food Programme’s executive director.

Beasley tweeted he was willing to meet Musk to provide more details, but it is not clear if the two explored the idea further.