“I care a great deal about retail investors,” he said during questioning by shareholder attorney Nicholas Porritt.

The case is a rare securities class action trial and the plaintiffs have already cleared high legal hurdles, with US Judge Edward Chen ruling last year that Musk’s funding post was untruthful and reckless.

Shareholders alleged that Musk lied when he sent the tweet.

Musk described the difficulties the company went through around the time he sent the “funding secured” tweet, including bets by short-sellers that the stock would fall.

“A bunch of sharks on Wall Street wanted Tesla to die, very badly,” he said, describing short-sellers, who profit when a stock falls in price. He said they planted false stories and said the practice should be made illegal.

Earlier, Tesla investor Timothy Fries told the jury that he lost $US5000 buying Tesla shares after Musk sent the tweet, which sparked volatile swings in the stock.

Fries said that “funding secured” meant to him that “there had been some vetting, some critical review of those funding sources”.

Musk’s attorney, Alex Spiro, told the jury in his opening statement on Wednesday that Musk believed he had financing from Saudi backers and was taking steps to make the deal happen. Fearing leaks to the media, Musk tried to protect the “everyday shareholder” by sending the tweet, which contained “technical inaccuracies”, Spiro said.

Guhan Subramanian, a Harvard Law School professor, told the jury that Musk’s behaviour in 2018 was “unprecedented” and “incoherent” in terms of structuring a corporate deal because he went public with his intent without proper financial or legal analysis.

A jury of six men and three women will decide whether the tweet artificially inflated Tesla’s share price by playing up the status of funding for the deal, and if so, by how much. Musk testified for less than 30 minutes before court adjourned until Monday.

Musk has previously contended he entered into the SEC settlement under duress and maintained he believed he had locked up financial backing for a Tesla buyout during meetings with representatives from Saudi Arabia’s Public Investment Fund.

The trial over his Tesla tweets come at a time when he has been focusing on Twitter, which he acquired in October after trying unsuccessfully to back out.

Musk’s leadership of Twitter – where he has gutted staff numbers and alienated users and advertisers – has proven unpopular among Tesla’s current stockholders, who are worried he has been devoting less time steering the automaker at a time of intensifying competition. Those concerns contributed to a 65 per cent decline in Tesla’s stock last year that wiped out more than $US700 billion in shareholder wealth – far more than the $US14 billion swing in fortune that occurred between the company’s high and low stock prices during the August 7-17, 2018 period covered in the class-action lawsuit.

Tesla’s stock has split twice since then, making the $US420 buyout price cited in his 2018 tweet worth $US28 on an adjusted basis now. The company’s shares were trading around $US133 on Friday, down from the November 2021 split-adjusted peak of $US414.50.

After Musk dropped the idea of a Tesla buyout, the company overcame its production problems, resulting in a rapid upturn in car sales that caused its stock to soar and minted Musk as the world’s richest person until he bought Twitter. He dropped from the top spot on the wealth list after the stock market’s backlash to his handling of the social media platform.

Reuters, AP