In a Tuesday press release, the agency claims that by delaying the filing of a beneficial ownership report by 11 days, Musk saved $150 million, or 0.34% on several subsequent tranches of stock he bought before filing the disclosure on April 4, 2022.

According to the agency, Twitter shares surged by 27% after Musk filed the ownership report - by which time he already owned 9% of the company's shares.

"Investors who sold Twitter common stock during this period did so at artificially low prices and thus suffered substantial economic harm," reads the complaint.

The agency wants Musk to disgorge any profits he incurred due to the late filing, along with pay a civil fine.

In response, Musk's attorney, Alex Spiro, told the Epoch Times that Musk did nothing wrong - calling the SEC's lawsuit a "sham."

"Today's action is an admission by the SEC that they cannot bring an actual case," he said, adding that Musk "has done nothing wrong and everyone sees this sham for what it is."

As the Epoch Times notes further, Spiro accused the SEC of running a "multi-year campaign of harassment" against Musk and insisted the agency was blowing the alleged late disclosure filing out of proportion, adding that this type of infraction carries a nominal penalty.

The lawsuit is the latest chapter in Musk's contentious relationship with the SEC. In 2018, the agency sued him for posting on social media that he had "funding secured" to take Tesla private at $420 per share, a claim that was later revealed to be exaggerated. The SEC contended that Musk's "misleading" post caused Tesla's stock price to jump by over 6 percent and led to "significant market disruption." That case was settled with Musk agreeing to pay a $20 million fine and step down as Tesla's chairman for three years. The settlement did not require Musk to admit to any wrongdoing.

Musk's "funding secured" post also sparked another lawsuit by a group of Tesla investors, who claimed that it was materially misleading and led them to suffer as much as $12 billion in financial losses. During a three-week trial in the case, Musk's attorneys argued that he believed his statements about taking Tesla private were truthful, citing discussions with Saudi Arabia's Public Investment Fund (PIF) as evidence of potential funding. Musk testified that PIF representatives showed strong interest in the deal, which led him to claim that the funding was secured.