Elon Musk becomes Twitter’s largest shareholder.

The Tesla chief executive, who has been critical of Twitter’s content moderation policies, has bought 9.2 percent of the social media company.

When Elon Musk mulled taking Tesla private in 2018, he posted on Twitter to tell the world about it

When he got stuck in traffic in 2016, he tweeted the idea of an underground tunnel system to alleviate

soul-destroying” congestion. And when he challenged President Vladimir V. Putin of Russia to one-on-one combat last month, he broadcast it on Twitter.

Now Mr. Musk is putting his money where he mouths off.

On Monday, a regulatory filing with the Securities and Exchange Commission revealed that Mr. Musk

the billionaire chief executive of Tesla and SpaceX and the world’s wealthiest person, had bought a 9.2 percent stake in Twitter,

the social media platform where he has over 80 million followers.