The US Securities and Exchange Commission (SEC) this week filed suit against former Twitter owner X Elon Musk on his purchases of Twitter stock in 2022.

The complaint alleges that Musk failed to timely disclose that he had purchased more than 5% of Twitter's common stock in March of that year.

The SEC said it allowed Musk to buy Twitter stock at an artificially low price, and he underpaid by $150 million.

An SEC rule requires investors who own more than 5% of a stock to disclose their holdings within 10 days, but the agency alleged in the complaint that Musk failed to disclose 11 days after the deadline when he owned 9%. .

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The US Securities and Exchange Commission this week filed a lawsuit against former Twitter owner Elon Musk over his 2022 purchase of Twitter stock. (Williams/CQ-Roll Call, Inc via Getty Images/Getty Images)

Twitter shares immediately skyrocketed after his announcement.

Musk started buying Twitter in April 2022. He finalized the sale in October.

He paid $44 billion for the social media platform.

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The complaint alleges that Musk failed to timely disclose that he had purchased more than 5% of Twitter's common stock in March of that year. (Photo Illustration: Muhammed Selim Korkutata / Anadolu Agency / Getty Images)

His attorney, Alex Spiro, told FOX Business: “Today's action is an admission by the SEC that they can't actually bring a lawsuit — because Mr. Musk did nothing wrong and everyone sees this fraud for what it is.”

He added: “As the SEC has stepped down and left office, the SEC's multi-year campaign of harassment against Mr. Musk has resulted in a single 13(d) complaint against Mr. Musk for alleged administrative malpractice. Failure to file a form – evidence even if it is an offense with a nominal penalty.”

This is the SEC's third lawsuit against Trump. The first of these involved a 2018 tweet by Musk claiming he was considering taking Tesla private for $420 a share. As part of the deal, he was forced to step down as Tesla's chairman.

The SEC also sued Musk in 2023 to compel him to testify about his Twitter purchases a year later.

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The current lawsuit is likely to be one of SEC Chairman Gary Gensler's last acts in office as the Trump administration takes office in less than a week.

Reuters contributed to this report.