Elon Musk, the billionaire chief executive of Tesla and the world’s wealthiest person, bought a nearly 10 percent stake in Twitter, the social media platform where he has more than 80 million followers and shares everything from business ideas and memes to, this past weekend, his experience at a famed Berlin nightclub.
The purchase, made public on Monday in a regulatory filing with the Securities and Exchange Commission, is worth about $2.89 billion based on the closing price of Twitter’s stock on Friday. News of Mr. Musk’s buy-in sent Twitter share prices soaring 25 percent.
The purchase, equal to 9.2 percent of the company, makes Mr. Musk Twitter’s largest shareholder. He has criticized the company in recent weeks for failing to adhere to free speech principles and openly considered starting a social network of his own that would be open source.
