Musk took several weeks to reveal his stake, violating federal law requiring disclosure within 10 days
A Twitter shareholder is suing Elon Musk for failing to disclose that he had bought a substantial stake in the company, affecting share prices.
The Tesla CEO revealed on 4 April that he had acquired a 9.2% stake in Twitter. Shares in the social media company soared, as investors viewed the move as a vote of confidence from the richest man in the world.