One of the most highly anticipated IPOs in recent memory, especially following the Lyft Inc LYFT 7.47% offering on the Nasdaq in March, shares of Uber NYSE:UBER got off to an inauspicious start Friday.

Rough Open

Not only did trading open at $42, below the IPO price of $45, but shares closed down more than 7 percent on the day. Despite that, demand for the stock was predictably high.

By 9:45 a.m. ET, two full hours before the stock opened for trading, more than 9,000 orders to buy Uber had been placed on TD Ameritrade Holding Corp. AMTD 0.09% alone, according to the company. In the first 10 minutes of trading, Uber represented about 8 percent of all equity trades made on the retail brokerage. By 1:30 p.m., that percentage had risen to 10 percent.

In all, Uber made up 10.3 percent of equity trades placed by TD Ameritrade retail investors on Friday. That’s well above first-day totals from Lyft (3 percent), Snap Inc SNAP 4.25% (5 percent) and LinkedIn (5 percent), but below Alibaba Group Holding Ltd BABA 0.69% (13 percent) and record-holder Facebook Inc FB 0.1% (22 percent).

Some Perspective

Some of that volume likely contributed from a commission rebate program the brokerage began on Friday, in which TD Ameritrade offered one online commission rebate to clients who bought or will buy Uber shares before May 16.

“We’ve sat with the exchanges and asked how we can make sure retail clients can get access,” said TD Ameritrade EVP of Trading Steve Quirk. “This would be a template that we could use to help companies with capital formation.”

Quirk added that depending on the reaction from Friday, the brokerage may offer the rebate program for future high-profile IPOs.

“We’re not trying to tell people when they should trade, we’re saying we believe in this [IPO] process. The fortunate thing we’ve seen with most of the people that trade IPOs is these people don’t buy and [then] sell that day.”

In terms of overall volume, more than 185 million shares of Uber traded hands on Friday, compared to 71 million shares for Lyft on its first day.

Uber's stock closed Friday's session at $41.57 per share, down 7.6 percent.