Tesla chief executive Elon Musk has sold $3.6 billion worth of shares in the electric vehicle firm, according to a filing in the United States Securities and Exchange Commission.

The sale happened around the same time this week when Bernard Arnault, the owner of luxury goods firm LVMH, displaced Mr Musk as the world's richest person.

Mr Musk has so far this year raised over $20 billion by selling his shares in Tesla. He has been raising money to pay for his $44 billion acquisition of Twitter.

The regulatory filing, however, does not mention the purpose of the latest share sale.

Mr Musk, 51, has seen his fortune fall by more than $100 billion since January to $168.5 billion, according to the Bloomberg Billionaires Index as of 10.20 am in New York on Wednesday.

Mr Musk's fall from atop the rankings - the first time that has happened since he was No. 2 in September 2021 - caps a tumultuous year for the frenetic billionaire.

He shocked the world in April with his offer to take Twitter private for $44 billion, in a brazen display of how the wealthiest individuals could wield their massive fortunes.

Tesla shares also extended declines to hit their lowest level in more than two years on Wednesday, as investors including a "fanboy" of Mr Musk lashed out at his distraction from the electric car company following his buy of Twitter.

"Elon abandoned Tesla and Tesla has no working CEO," KoGuan Leo, the third largest individual shareholder of Tesla, who describes himself of Mr Musk's "fanboy," tweeted on Wednesday.

"Are we merely Elon's foolish bag holders?" he said. "An executioner, Tim Cook-like is needed, not Elon."