Apple's primary assembly partner, Hon Hai -- better known as Foxconn -- saw its revenues drop approximately 20 percent in December, on top of missing full-year sales predictions from analysts.
The company reported December revenue of $12.3 billion, coincidentally about a 20 percent drop both month-to-month and year-over-year, according to Reuters. Annual revenues were up 6.42 percent, but that figure was below an averaged analyst consensus calling for 7 percent.
December numbers were as expected, Hon Hai said in an official statement.
A variety of Apple suppliers, such as Catcher and TPK, have either seen lower-than-expected December figures or had to adjust their 2016 spending. Along with Foxconn's data, trends appear to back a Nikkei claim that Apple is cutting its iPhone 6s/6s Plus production by about 30 percent.
The slower production has been attributed to an "inventory adjustment" rather than weak demand, giving vendors a chance to clear out stockpiled units. Demand for iPhones also typically tapers off after the Christmas season, remaining reasonably healthy until just a month or two before new models are announced -- at which point some buyers may decide to wait.