Apple's first foldable iPhone, the "iPhone Duo," is increasingly likely to face shortages early in its launch.

On Sept. 15 local time, IT outlet 9to5Mac reported that Jeff Pu (제프 푸), an analyst at GF Securities, lowered his 2026 shipment forecast for the iPhone Duo to 6 million units from 7 million. The drop in supply was attributed to production disruption caused by "hinge constraints," not weak demand.

In a research note, Pu said constraints in hinge production are slowing the pace of iPhone Duo manufacturing. That has raised the possibility that early supply will be lower than previously expected.

The iPhone Duo is Apple's first foldable iPhone unveiled last week. Unlike the iPhone 18 Pro and iPhone 18 Pro Max, it is scheduled for an October launch rather than September. Preorders begin on Oct. 16, with first deliveries set for Oct. 23.

Pu estimated shipments of the iPhone 18 Pro and iPhone 18 Pro Max at 72 million units through year-end. That is about 12 times his 2026 iPhone Duo shipment forecast of 6 million units.

The price is also high. The iPhone Duo starts at 3.29 million won, the highest starting price of any iPhone to date. Pu said the direct cause of the current supply reduction is hinge production constraints, not pricing or demand.

If early iPhone Duo supply is limited, competition to secure units could emerge from the preorder stage. As Apple's first foldable product, attention is focused on how much hinge production constraints will affect supply after the actual launch.