The US Securities and Exchange Commission (SEC) has filed a lawsuit against Elon Musk, alleging that he failed to disclose his stake in Twitter, which enabled him to purchase shares at artificially low prices. The lawsuit claims that the Tesla CEO saved $150 million in share purchases as a result of this omission. According to SEC regulations, investors must report if their holdings exceed 5% within 10 days, but Musk reported it 21 days after the purchase. Musk's lawyer referred to the lawsuit as a sham and harassment campaign. Twitter's stock price surged over 27% after Musk's share purchase was made public, leading to his eventual acquisition of Twitter for $44 billion in October 2022. The SEC filed the complaint in a federal court in Washington, requesting Musk to relinquish unjust profits and pay a fine. SEC Chairman Gensler announced his resignation in anticipation of Donald Trump's return to the presidency. This development follows past clashes between Musk and the SEC, including a previous case in 2018 involving Musk's misleading comments on taking Tesla private.