Tesla CEO Elon Musk has bought a large stake in Twitter, making him the largest outside shareholder in social media shares, shortly after he criticized the company for what he attributed to its failure to uphold the principles of freedom of expression. CNBC" (CNBC).

Musk now owns 73,468,938 shares of Twitter, which represents a 9.2% stake in the company, according to a Securities and Exchange Commission filing released Monday. The stake is worth $2.89 billion based on Twitter's closing price last Friday.

The purchase comes less than two weeks after Musk criticized the company, as he polled people on Twitter about whether it adhered to the principles of freedom of expression.

"Given that Twitter serves as a de facto public platform for discussion, failure to adhere to the principles of freedom of expression fundamentally undermines democracy," Musk wrote in a tweet.

Given that Twitter serves as the de facto public town square, failing to adhere to free speech principles fundamentally rocks democracy.

What should be done?

https://t.co/aPS9ycji37

— Elon Musk (@elonmusk) March 26, 2022

Late last month, Musk also said he was considering building a new social media platform.

Musk's purchase of that large stake in Twitter shares pushed the company's share price to rise by more than 27%.

"Musk could try to take a more aggressive stance here on Twitter," Dan Ives, an analyst at Wedbush, a private investment firm in Squawk Box, told CNBC. "This could eventually lead to some kind of takeover," he added.

"It makes sense given what Musk was talking about, at least from a social media perspective, in building a new social network," Ives added.

Musk's share in Twitter is greater than its founder

Musk is a frequent Twitter user and has more than 80 million followers on the platform, however some of his tweets have made him nervous over the years with Twitter founder Jack Dorsey.

This stake makes Musk the largest shareholder in the company, with more than 4 times the share of Jack Dorsey, which is 2.25%.