Tesla CEO Elon Musk has become Left-wing social media platform Twitter’s largest shareholder, taking 9.2% stake in Twitter Inc.

Musk now has four times as many shares as Twitter founder Jack Dorsey, who owns 2.25%.

“Twitter shares surged about 26% in premarket trading after the regulator filing released Monday detailing Musk buying the holding,” Bloomberg reported. “The stake is worth about $2.89 billion, based on Friday’s market close.”