And a rare sales forecast slash may bode poorly for the rest of the year.
In a letter to investors on Wednesday, Apple CEO Tim Cook warned that the company's fiscal first-quarter revenue would be weaker than previously expected.
The weaker holiday season -- a critical period in which most of Apple's iPhones are sold -- will fan growing belief that the company is struggling with consumer fatigue for its popular smartphone and that sales may be on a downward slide.
"iPhone units are likely down, and I believe prices on the more premium, higher-priced phones are down due to holiday discounting," said Patrick Moorhead, an analyst at Moor Insights.
The warning prompted concerns similar to those Apple endured more than a decade ago, when it missed its fiscal fourth-quarter numbers amid an economic downturn.
Then-CEO Steve Jobs broke his practice of skipping analyst calls in order to quell investor fear, reiterating that Apple would be fine.