"Apple is quite conservative in terms of placing new orders for upcoming iPhones this year", one supply chain source told the Nikkei Asian Review.
"At least part of this lower order forecast probably relates to Apple just being a little more realistic", he said.
Yuanta Securities Investment Consulting says that Foxconn will assemble 100% of the 5.8-inch model, 80% to 90% of the 6.5-inch "Plus" version, and 30% of the 6.1-inch LCD model.
Apple fell 2.1 per cent in US pre-market trading, after its Frankfurt-listed shares also lost as much as 2.1 per cent. Supplier AMS AG dropped as much as 6.7 per cent. Dialog's shares had slumped 17 per cent last Friday after it said Apple would cut orders for its power-management chips by around 30 per cent this year.
Apple may well be preparing for smartphone fatigue with its conservative estimate, or this report might be flat out wrong like those which pegged the firm's iPhone X as a failure previous year.
If accurate, the report could simply suggest that Apple plans to avoid a repeat of the 2017-2018 iPhone X, iPhone 8, and iPhone 8 Plus scenario, where phones became abundantly available to interested customers relatively quickly after their release rather than being subject to major shortages - the latter a false sign of success that's paired with consumer disappointment. "Apple is doing enough, in general, to keep the ball moving forward".
Apple did not immediately respond to a request for comment.
The iPhone is by far the biggest revenue generating product from Apple.