https://www.cnet.com/news/apple-warns-of-weaker-first-quarter-revenue/

The warning is similar in vibe to the concerns Apple endured more than a year ago, when it missed its fiscal fourth-quarter numbers amid an economic downturn. Then-CEO Steve Jobs had to join the call to quell investor fear, reiterating Apple would be fine. (He was right.)

Cook blamed much of the shortfall in China, where the company underestimated the deceleration in the economy. The company saw a decline in sales of iPhones, Macs and iPads in the country.