Shares of the ride-sharing giant Uber Technologies (UBER 9.27%) rose nearly 9%, as of 12:38 p.m. ET today, after billionaire investor Bill Ackman revealed that his fund Pershing Square Capital Management had launched a new stake in the company that is now valued at over $2 billion. That would make the position the largest in Pershing's 11-stock portfolio, based on values at the end of the third quarter.

Ackman has always been a fan

On social media platform X, Ackman tweeted today that his fund began building the Uber position in early January and today owns 30.3 million shares. Based on a current share price of $75.58, as of this writing, that equates to over a $2.3 billion stake. In the third quarter, Pershing's largest position was Brookfield Corp, valued over $1.7 billion.

Ackman said he was a day-one investor in Uber through a small investment he had in a venture fund, and has always been a big fan of the company. He wrote:

We believe that Uber is one of the best-managed and highest-quality businesses in the world. Remarkably, it can still be purchased at a massive discount to its intrinsic value. This favorable combination of attributes is extremely rare, particularly for a large-cap company.

Ackman also said that Uber has struggled due to "erratic management." However, since CEO Dara Khosrowshahi took the reins in 2017, he has made Uber a very profitable company that generates significant cash flow.

Looking bullish from many angles

Uber's stock is now up roughly 17% this week. The company reported fourth-quarter earnings earlier this week that failed to impress, but analysts came to the rescue and said the market was missing some pretty impressive numbers, such as stronger-than-expected revenue and bookings.

The stock trades at about 23 times forward earnings and could have a big role to play in the autonomous vehicle market. That, coupled with its impressive financials such as growing revenue, free cash flow, and profits, make Ackman's new holding an appealing one to hitch a ride with.