“We’ve never been in this situation before, where Apple has announced two devices coming out within six weeks of each other,” an official at one carrier said.

Apple did not return a request for comment. The major carriers—AT&T, Verizon, Sprint, and T-Mobile—weren’t saying much about iPhone 8 preorders, either. “It’s clear customers are super excited about Apple’s new products and so are we,” a spokeswoman for T-Mobile said. “We’re looking forward to yet another successful launch with Apple.” AT&T, Verizon, and Sprint declined to comment.

Apple unveiled the iPhone 8 and X at a press event on its new Apple Park campus last week and preorders for the iPhone 8 and iPhone 8 Plus began on Friday. These new iPhones look much like Apple’s models from the past three years, though with faster processors, better cameras, and a glass back instead of aluminum to support inductive charging. Apple also decided to slightly raise the price of the iPhone 8 and 8 Plus from the comparable devices last year.

But the iPhone X—which has an all-new exterior design, sharper OLED display, and a price tag starting at $999—isn’t immediately available. Preorders begin at the end of October for a scheduled November 3 delivery. And rumors abound that supplies may be very tight.

News of underwhelming interest and preorders for the iPhone 8 are consistent with a research report by KGI Securities analyst Ming-Chi Kuo on Monday. Kuo noted that shipping delays of only one week or so currently showing on Apple’s web site for the iPhone 8 are much less than the three- to six-week delays seen after earlier iPhone launches.

Overestimating demand for the iPhone 8 models could hurt Apple if it produced too many units for sale ahead of time or can’t keep pace with higher-than-expected demand for the iPhone X model. But if Apple can produce enough of the iPhone X to satisfy the demand, it could beat the forecasts by selling more of the high-priced model than analysts expected.

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Analysts are counting on robust sales of the iPhone 8 models to help Apple (AAPL) meet its revenue prediction of between $49 billion and $52 billion for the current quarter, the company’s fiscal fourth quarter of 2017 which ends at the end of this month. Sales would need to increase from last year by 4% to 11% to meet the forecast.

The bigger question is how iPhone oversupplies or shortages might effect the more significant holiday shopping quarter. Last year, Apple reported record revenue of $78.4 billion, 69% from iPhone sales. This year, Wall Street analysts expect Apple will bring in almost $87 billion, up 11%, thanks to a predicted heady 14% gain in iPhone revenue.

Apple’s stock price, which had been on a tear ahead of the iPhone announcement event, has been little changed since as investors await more information on early sales. Like last year, but unlike many prior years, Apple did not announce how many iPhones had been preordered in the first weekend. Apple shares hit an all-time high of $164.94 on September 1, but have since fallen back a bit and were trading at $159.29 in midday on Tuesday.

With competition somewhat muted in the wireless market this year, the carriers also have not been offering the same lucrative trade in deals to iPhone buyers that they did in 2016. AT&T (T), Verizon (VZ), and T-Mobile (TMUS) are offering only about half price on a new iPhone with a trade in, while Sprint (S) has a full-price trade-in deal but only for customers who add a new line and return one of the five most recent smartphones available.