Apple said that its revenue guidance for its first fiscal quarter, which ended in December, was going to be significantly lower than it expected, the iPhone giant announced in a press release on Wednesday.

Apple had previously told investors to expect revenue between $89 billion and $93 billion.

On Wednesday, it revised that estimate down to $84 billion, 7.6% lower than it previously expected.

"If you look at our results, our shortfall is over 100% from iPhone and it is primarily in greater China," Apple CEO Tim Cook said in an interview on CNBC.

"So we have sort of a collection of items going on, some that are macroeconomic and some Apple specific," he continued.

Issues this quarter cited by Apple include:

  • Difficult comparisons due to iPhone launch timing.
  • A strong US dollar.
  • Supply constraints.
  • Economic weakness in emerging markets, especially China.
  • iPhone upgrades weaker than expected.
  • Fewer carrier subsidies artificially reducing the sticker price of a smartphone.
  • A program in which Apple replaced iPhone batteries for $29.

"In addition, these and other factors resulted in fewer iPhone upgrades than we had anticipated," Apple said in a letter to investors attributed to Cook.

Apple stock declined over 8% in after-hours trading. The stock had already declined over 30% from its high in October after Apple said that it would no longer provide unit sales numbers to investors.

Before Wednesday's news, analysts and investors had already been getting increasingly bearish on Apple stock in the midst of its worst slump in over a decade. In addition, many Apple products were advertised with discounted prices after device trade-ins, suggesting that sales were slow.

Apple will officially report its holiday quarter earnings on January 29.

Here's the entire letter:

To Apple investors:

Today we are revising our guidance for Apple's fiscal 2019 first quarter, which ended on December 29. We now expect the following:

Revenue of approximately $84 billion Gross margin of approximately 38 percent Operating expenses of approximately $8.7 billion Other income/(expense) of approximately $550 million Tax rate of approximately 16.5 percent before discrete items

We expect the number of shares used in computing diluted EPS to be approximately 4.77 billion.