Elon Musk’s newly disclosed 9.2% stake in Twitter Inc. has made him the largest shareholder of the social media-company, topping co-founder and former Chief Executive Jack Dorsey and elbowing out numerous financial institutions.

Mr. Musk reported owning almost 73.5 million shares of Twitter as of March 14, according to a securities filing Monday.

His…

Elon Musk‘s

newly disclosed 9.2% stake in
Twitter Inc.
has made him the largest shareholder of the social media-company, topping co-founder and former Chief Executive

Jack Dorsey
and elbowing out numerous financial institutions.

Mr. Musk reported owning almost 73.5 million shares of Twitter as of March 14, according to a securities filing Monday.

His disclosure prompted Twitter’s stock to surge 27% on Monday, its biggest-ever one-day gain. That rally means Mr. Musk made about $784 million in paper profits in one trading day.

His stake is now worth $3.7 billion based on Monday’s closing price.

Mr. Musk’s stake bumped Vanguard Group from Twitter’s top shareholder to No. 2, according to FactSet.
Morgan Stanley
Investment Management Inc. slid to No. 3.

Vanguard and Morgan Stanley declined to comment.

Mr. Dorsey, the only individual other than Mr. Musk who made the top 10 shareholder list, dropped one spot to No. 7. Representatives for Mr. Dorsey didn’t respond to a request for comment.

Jack Dorsey is the only other individual in Twitter’s top 10 shareholder list.
Photo: jim watson/Agence France-Presse/Getty Images

Mr. Musk is the world’s richest person with a net worth of $273 billion as of Monday, according to the Bloomberg Billionaires Index. He runs electric-vehicle company
Tesla Inc.
as well as rocket company Space Exploration Technologies Corp., as SpaceX is formally known, and tunneler The Boring Co.

Mr. Musk didn’t disclose plans or intentions behind his Twitter purchase. On Monday he tweeted: “Oh hi lol.”

Twitter CEO

Parag Agrawal
owns about 507,000 shares of Twitter as of March 1, representing a stake of $19.9 million based on Friday’s closing price, according to FactSet. He became CEO late last year.

Here’s a list of the top 10 Twitter shareholders, according to FactSet.

In 2021, billionaire CEO Elon Musk reached several milestones across Tesla, SpaceX and Starlink. WSJ reporters Rebecca Elliott and Micah Maidenberg break down some of his biggest moments in 2021 and what’s to come in 2022. Illustration: Tom Grillo

Write to Joseph De Avila at joseph.deavila@wsj.com and Will Feuer at Will.Feuer@wsj.com