https://techcrunch.com/2019/01/02/apple-lowers-guidance-on-q1-results/

Apple CEO Tim Cook issued a letter today, revising guidance for the company’s Q1 fiscal results. Per the letter, revenue has been shifted from an initial projection of between $89 billion and $93 billion to $84 billion. The note highlights a number of reasons for dropping the number, including, perhaps most notably, lower than expected results in emerging markets.

“While we anticipated some challenges in key emerging markets, we did not foresee the magnitude of the economic deceleration, particularly in Greater China,” Cook says in the letter. “In fact, most of our revenue shortfall to our guidance, and over 100 percent of our year-over-year worldwide revenue decline, occurred in Greater China across iPhone, Mac and iPad.”