Why Japan yen problem matters beyond BOJ rate hike
The Bank of Japan raised its policy rate 25 basis points to 1.25% on September 18th, taking borrowing costs to their highest level in 31 years.
The significance extends well beyond Japanese interest rates. With the yen having traded at levels not seen since the 1980s, Bloomberg’s video below provides useful background on why Japan’s currency has become an issue for households, global investors and even the US Treasury.
With today’s hike now delivered, it also helps explain why the pace and direction of the BOJ’s future policy moves will still be watched so closely around the world.
Key Points
The yen’s weakness isn’t just a Japan story. Bloomberg argues that it now has direct implications for US borrowing costs and global financial markets.
In July 2026, the yen fell to around ¥164 to the US dollar, compared with roughly ¥102 five years earlier - a dramatic shift with winners and losers on both sides of the Pacific.
For Japan, the weak yen boosts tourism and exporters, but it also makes imported energy and other essentials more expensive, putting pressure on household purchasing power.
The bigger international connection is US Treasuries. Japan is a major holder of US government debt, and Bloomberg explains why efforts to defend the yen can potentially push American bond yields higher.
That helps explain why US Treasury Secretary Scott Bessent has been unusually vocal about Japan’s monetary policy and the yen - and why Washington has its own reasons to want a more stable Japanese currency.
The video also looks at the yen carry trade, where investors borrow cheaply in Japan and deploy that money into higher-yielding assets elsewhere - a strategy that has become an important source of liquidity across global markets.
The difficult question is what happens next. Higher Japanese interest rates could strengthen the yen, but moving too quickly risks damaging the economic growth policymakers are trying to protect.
