With $2.9bn Twitter stake, Musk now owns 4 times more shares than founder Dorsey, stock soars 21%

Not long after denouncing the company for failing to maintain the fundamentals of free speech, Tesla and SpaceX CEO Elon Musk bought a substantial shares in Twitter, making him the social media business's largest outside stakeholder.

According to a Securities and Exchange Commission 13G report issued Monday, Musk holds 73,486,938 shares of Twitter, representing a 9.2 percent passive ownership in the firm.

Based on Twitter's closing price on Friday, the stake is worth $2.89 billion.

The purchase comes less than two weeks after Musk chastised the company on Twitter, asking followers on whether it upholds free speech values.

Tesla CEO Elon Musk announced in late March that he was considering creating a new social networking platform.

He conducted a Twitter poll in which over 70% of people said they did not believe Twitter adhered to the principle of free expression.

"Is a new platform needed?" Musk then asked, implying that Twitter was damaging democracy by failing to adhere to free speech norms.

Musk now owns the most shares in Twitter, making him the company's largest stakeholder.

His stake is also more than four times that of founder Jack Dorsey, who owns 2.25 percent of the company's outstanding stock.

Musk's 9.2 percent holding puts him ahead of Vanguard Group (which owns 8.79 percent), Morgan Stanley Investment Management (which owns 8.08 percent), and BlackRock Institutional Trust Company (which owns 8.08 percent) (4.56 percent ).

With over 80 million followers, Musk is one of Twitter's most popular users.

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(With inputs from agencies)