https://www.cnbc.com/2018/11/13/goldman-sachs-cuts-apple-iphone-estimates-on-negative-supplier-outlook.html

Goldman Sachs estimates Apple will produce 6 percent fewer iPhones next year than previously expected after key supplier Lumentum reduced its shipment outlook, according to a report Tuesday.

"We are concerned that end demand for new iPhone models is deteriorating," Goldman said in the note. "We note this could easily right itself given the bulk of demand comes in late December but we feel more prudent sell through forecasts are warranted due to the timing and magnitude of this warning."