“It’s the Lyft effect,” said Kathleen Smith, a principal at Renaissance Capital who manages an I.P.O. fund. “This is what Uber should try very hard to avoid — it should not have a stock that breaks its I.P.O. price.”

Uber’s potential $100 billion valuation was earlier reported by Reuters and The Wall Street Journal.

Uber is expected to publish its public offering prospectus on Thursday, giving investors a closer look into its businesses. That document will not provide any information on the offering’s potential price, but the company recently disclosed its latest thinking about its own valuation to some investors.

In a notice to holders of some of its convertible bonds last week, Uber said that its stock could be valued at $48 to $55 a share, said the people briefed on the situation, who asked not to be identified because the details were confidential. That would translate into a valuation of about $90 billion to $100 billion for the company, factoring in the roughly $10 billion that it expects to raise.

The people briefed on the matter cautioned that the I.P.O. process was continuing and that it was too early to determine what Uber’s valuation would ultimately be. The company’s underwriters, led by Morgan Stanley and Goldman Sachs, could still raise the price of the shares — and therefore its valuation — in the coming weeks if there is enough interest from prospective shareholders.