Uber’s stock extends its surge as hedge funder Ackman says he’s amassed a 30.3-million-share stake since early January.

The hedge fund manager said his fund began buying Uber shares in early January and has amassed 30.3 million shares, worth $2.3 billion.

Shares of Uber Technologies jumped to a three-month high on Friday after billionaire hedge fund manager Bill Ackman announced that he had taken a position in the ride sharing platform.