A regulatory filing shows that Musk has taken a big stake in the company.
According to the Securities and Exchange Commission 13G filing, Musk has a 9.2% passive stake in the company. Based on the closing price on Friday, the stake is worth over $2 billion.
While it is classified as a passive stake, investors were bidding higher on the chance that it could lead to something more.
"Musk could try to take a more aggressive stance on the platform," said Dan Ives on CNBC.
Following the news, the shares of the social network surged more than 25% in the premarket.
Musk has more than 80 million followers on the platform. Over the years, he's gotten the chief into hot water for some of his posts.
On August 7, Musk said he had secured funding to take the company private at $420 per share. Musk and his shareholders had a roller coaster of a year. The company set performance records, but also had to deal with litigation, government inquiries and layoffs. The SEC removed Musk from his role as chairman of the company.
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