Elon Musk cheated Twitter shareholders by waiting too long to disclose his growing stake in the company, the U.S. Securities and Exchange Commission claims.

The SEC has sued billionaire X owner Elon Musk, alleging he failed to disclose his ownership of Twitter stock in a timely manner in 2022.

Twitter's stock price rose 27 percent once Musk belatedly disclosed his stake, the lawsuit said. "During the period that Musk was required to publicly disclose his beneficial ownership but had failed to do so, he spent more than $500 million purchasing additional shares of Twitter common stock," it said.