The decline in USD/JPY accelerated sharply in September. The move cannot be explained solely by a narrowing US-Japan interest rate differential, and is said to have reflected overlapping changes in supply and demand, including large-scale intervention.
The decline in USD/JPY accelerated sharply from September onward. The move gained momentum against a backdrop of a narrowing US-Japan interest rate differential, but reportedly developed into a plunge of around ¥7 in approximately one week.
The article argues that the plunge cannot be fully explained by the US-Japan interest rate differential alone, and examines its relationship with factors including movements in long-term interest rates and concerns about fiscal discipline. It suggests links through financial indicators and charts.
Japan's foreign-exchange intervention exceeded at least ¥27 trillion in 2026, far surpassing the previous annual record. It portrays a situation in which the yen's depreciation trend continued despite the intervention.
The trade and services deficit was reportedly ¥4 trillion in 2025 and ¥21 trillion in 2022, its highest level on record. The article suggests that the scale of intervention may have reached a level exceeding these amounts. It also points to the unwinding of speculative positions as a contributing factor.