Ahead of Apple's quarterly earnings report on Tuesday, analysts agree on one thing: The latest iPhone iteration will not deliver the mega sales enjoyed by the iPhone 6 line around its launch.
"The evidence thus far suggesting that demand for iPhone 6s is not as frothy as last year is tough to ignore," Susquehanna Financial Group analyst Chris Caso wrote in a note on Thursday.
Caso, who has a positive rating on the stock and a $155 price target, has reduced his estimate for iPhone fourth quarter sales from 79 million to 74 million, representing a year-over-year decline of 0.6 percent. That estimate is just slightly below the consensus of 75 million. Apple derives more than 60 percent of its revenue from iPhone sales, so investors watch the number of units sold closely.
The company said it sold 13 million iPhone 6s and 6s Plus devices during its first weekend of sales — 3 million more than in the same period last year — but analysts point out that this year's number includes China.
Many also note that Apple launched its new line of smartphones a week later this year, so its fourth quarter results will include just two days of sales, versus the eight included in its fourth quarter 2014 results.
Analysts expect Apple to report earnings per share of $1.88 on revenue of $51.1 billion, according to Thomson Reuters. That is just above company guidance for the 2015 fourth quarter of $49 billion to $51.1 billion and would represent a 21 percent jump over last year.
When it comes to predicting just how much demand for the latest version of the company's new smartphones may have slowed, expectations vary widely.
"Given how much consumers use smartphones, we believe the incremental value of the newest iPhone model will continue to justify its purchase for the vast majority of iPhone buyers. However, we will be watching closely to see if consumers begin to opt for savings over new features," Pacific Crest Securities analyst Andy Hargreaves wrote in a report earlier this month.
But Alex Gauna, analyst at JMP Securities, said Monday that bearish analysts are missing Apple's potential in global markets.
"I think there are a lot of investors that are worried about the tough compares from the 6 to the 6S, as well as the saturation, arguably, in North American and Western markets," Gauna said on CNBC's "Squawk on the Street." "But what that fails to takeinto consideration is the still-massive global opportunity for Apple."
Hargreaves expects Apple's fourth-quarter results to be in line with consensus expectations, but guidance for Q1 revenue will fall short of the Street estimate of $76.4 billion.
"We continue to believe Street estimates for the first half of fiscal 2016 iPhone units are too high, but Apple's price and the stickiness of iPhone customers should protect long-term cash flow, which creates favorable long-term risk/reward," Hargreaves wrote.
Tigress Financial Partners' Ivan Feinseth said he's less worried about the number of iPhones sold, and more interested in the amount of profit from them — a number he expects to be strong, he told CNBC's "Power Lunch."
"Even if the reaction in the stock is negative, I believe the report will be positive, and Apple as a stock is so unbelievably cheap, I think it will over time, continue to go higher," Feinseth said.
What management says on the earnings call about expectations for the all-important December holiday quarter is likely to have more impact on the stock than the earnings numbers, which many analysts believe are already baked in.
"The issue of unit demand gets pulled forward." BGC analyst Colin Gillis said in an earnings preview report on Friday. "Any weakness in iPhone sales in the December quarter may add fuel to the concern that the smartphone cycle is slowing, and drive shares of Apple lower. We see risks highly skewed to the downside."
Gillis has a hold rating on the stock and a $115 price target and expects the company to report $52 billion in revenue and earnings per share of $1.95, up from $1.42 in the prior year and $1.85 in the prior quarter. Apple's stock was at $115.24 midday Monday, down 3.86 percent.
Apple remains Piper Jaffray's top large cap pick for the rest of the year and heading into next year: "One of the biggest questions around the stock is how iPhone growth will fare against difficult iPhone 6 comps starting in December 15," analyst Gene Munster wrote in a note Thursday. "Based on conversations with 15 investors over the last week, we believe that expectations are for iPhones to be down slightly year over year."
Munster believes negative sentiment around iPhone 6s sales is overblown: "We continue to believe that the iPhone 6s cycle will be not as bad as investors expect and remain comfortable with our thinking for two percent year over year iPhone growth in December 15."
Of course, Apple launched a slew of other new products this year ,and analysts will also be watching for hints about management expectations for holiday sales. "We believe Apple Watch will be a major hit this holiday season," Drexel Hamilton analyst Brian White wrote in a note out earlier this month.
The company has refused to disclose Apple Watch shipment numbers, with CEO Tim Cook simply saying at a conference last week: "We shipped a lot the first quarter, then last quarter we shipped even more. And I can predict this quarter we will ship even more."
White, who has a buy rating on the stock and a 12-month price target of $200, is bullish: "Apple is innovating like never before with entry into the first new product category in five years with the Apple Watch, the launch of new services such as Apple Pay, an expanded effort in the TV market with the all-news Apple TV and investment in big, new industries such as the auto market that we believe could lead to an Apple Car."
Hargreaves, on the other hand, sees Apple's other products as ancillary compared to the iPhone.
"I'm sure it will sell a lot of units this Christmas, people will go out and buy them," Hargreaves said of the Apple TV on CNBC. "But I don't think it moves the needle for Apple. "
Apple reports earnings after the bell on Tuesday and will discuss the results on an investor call at 5 p.m. EDT.
Correction: This story has been updated to reflect the correct day Apple announces earnings.