Tesla CEO revealed on April 4 that he had acquired a 9.2% stake in Twitter. Shares of the social networking company soared as investors saw the move as a vote of confidence by the richest man in the world. However, federal commercial laws require investors to notify the Hellenic Capital Market Commission (SEC) after exceeding a 5% stake in a company within 10 days. Musk acquired his stock on March 14 but did not release it until April 4. In the interval between the 5% threshold and the public report, Musk was able to buy additional shares at a deflated price, according to the new lawsuit. Experts estimate that the delay may have illegally led to Musk $ 156 million. Filed in federal court in New York on Tuesday, the lawsuit seeks group action on behalf of investors who sold Twitter shares during that period and lost the profits they would have realized if Musk had disclosed his share earlier. Shares of Twitter rose 27% – from $ 39.31 to $ 49.97 after Musk revealed his stake. The plaintiff sold 35 shares of Twitter for $ 1,373, or an average price of $ 39.23, before Musk revealed his investments. Jeffrey Block, of the law firm representing the plaintiff, confirmed that the lawsuit had been filed since Tuesday. The lawsuit seeks trial of jurors for unspecified damages and punitive damages. Musk did not immediately respond to a request for comment. The Hellenic Capital Market Commission did not immediately respond to a request for comment on whether it would take action against Musk. Musk’s announcement that it had acquired a 9.2% stake – making it the company’s largest shareholder at the time – sparked immediate controversy. Many speculated that the acquisition could allow Musk, a vocal Twitter critic, to push the company to make broader changes. Twitter announced on April 5 that Musk would join its board, but on Sunday, Twitter CEO Parag Agrawal abruptly announced that Musk would not eventually become a board member. If he does not become a board member, Musk, a productive Twitter user, can continue to buy shares without committing himself to a 14.9% stake in his deal with the company. Following the news of the reversal, Musk wrote on Twitter and then deleted an emoji by hand. Reuters contributed to this report