Uber’s shares began trading about $2 below its initial public offering price of $45.

Traders scratched their heads Friday, trying to remember a high-profile IPO like Uber going south on the first day.

Shares of Lyft, a rival in the ride-sharing business, are tumbling 6%. That company has had a very rough time since it went public at the end of March. It hit a new all-time low Friday.

CEO Dara Khosrowshahi tried to control expectations, telling CNBC that Uber investors are in it for the long ride. He says the company will be judged on what it does in three to five years.