Elon Musk cheated Twitter shareholders out of more than $150 million by waiting too long to disclose his growing stake in the company as he prepared a takeover bid, the US Securities and Exchange Commission claimed in a lawsuit filed days before the Trump administration takes over.

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.

Regulators filed a lawsuit in federal court stemming from Mr. Musk’s $44 billion purchase of the social media company now called X.