Throughout the morning, indications of Uber's opening trade price dropped from an initial estimate of $46 to $48, until it opened at $42 per share. That's below the $45 price of shares sold in its initial public offering, and even below the $44 low point of the company's estimated pricing range last week . Uber closed at $41.57.

Shares of ride-hailing company Lyft fell 7.4% on Friday after larger rival Uber had a disappointing debut on the New York Stock Exchange, closing down 7.6%.

Uber is becoming a public company during a week of back-and-forth tensions over trade negotiations between the U.S. and China. On Friday morning the major indexes were all down at least 1%, though they turned around later in the day and all finished up.

Lyft was having a rough week already. The shares fell more than 10% Wednesday after the company released its first earnings report since going public.

Lyft had a stronger opening than Uber when it started trading on March 29. The company priced shares at $72 each, then the stock began trading at $87.24. The shares moved lower, and the closing price on the first day of trading was $78.29, but that was still above the IPO price.

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