Japan just got some serious help defending its battered currency. The United States joined Japan in buying yen after months of heavy selling pushed the currency to levels not seen in roughly four decades.
The coordinated action carries weight because Washington rarely steps directly into currency markets. It marked the first joint U.S. and Japanese yen-buying intervention since 1998, while also becoming the first coordinated currency intervention involving the United States since the 2011 response to Japan’s earthquake and tsunami.
The move came after the yen sank to 163.99 against the U.S. dollar in July. That weakness was becoming increasingly painful for Japan, since a cheaper yen raises the cost of imported fuel, food, and other goods priced in dollars.
Japan had already been fighting back on its own. Between April 28 and May 27, Japanese authorities conducted foreign exchange interventions totaling ¥11.73 trillion, according to Japan’s Ministry of Finance.
Why Japan and the U.S. Stepped Into the Yen Market?
This time, the United States added something Japan could not easily create alone, surprise and international credibility. Traders who had grown comfortable betting against the yen suddenly had to consider the possibility that two major governments were prepared to fight them together.
The intervention delivered an immediate jolt. The yen climbed by more than 1% during the coordinated operation and eventually strengthened to around 155.20 per dollar, its strongest level since early May. That was a sharp reversal from the 163.99 level reached during July’s selloff.
The amounts involved were also substantial. Estimates based on central bank data suggested Japan may have spent roughly $36.6 billion during the coordinated operation. The intervention followed another major Japanese effort immediately beforehand, showing just how aggressively Tokyo was prepared to defend its currency.
The Yen Jumped, but the Real Problem Still Exists
The intervention clearly caught traders’ attention, but it did not erase the forces pushing the yen lower. By mid-August, the currency had weakened again to roughly 159.50 per dollar, giving back a meaningful part of its initial gain.
That retreat explains why analysts remain cautious about calling the intervention a lasting victory. Governments can make betting against a currency painful, but they have a much harder time changing its long-term value when interest rates and economic conditions keep pulling in the opposite direction.
The biggest issue remains the gap between Japanese and U.S. interest rates. The Bank of Japan raised its benchmark rate to 1% in June, its highest level in decades, but U.S. rates remain considerably higher. That gap gives investors a reason to borrow cheaply in yen and move money into higher-yielding assets elsewhere.
This strategy is commonly known as the ‘yen carry trade.’ It can work well while the yen remains weak and interest-rate differences stay wide. A sudden yen rally, however, can quickly turn those positions against investors and force them to unwind trades.
Now the Pressure Shifts to the Bank of Japan
Expectations for another Bank of Japan rate increase have strengthened as the currency remains vulnerable. Former top Japanese currency diplomat Mitsuhiro Furusawa said the central bank may need to signal a faster path toward higher rates, with markets increasingly watching September for another possible move.
Higher Japanese rates could make holding yen more attractive and reduce the appeal of borrowing the currency for carry trades. They could also narrow the gap with U.S. interest rates, attacking one of the fundamental reasons investors have favored dollars over yen.
The challenge is that higher rates come with costs. Japan carries an enormous public debt burden, and more expensive borrowing can put additional pressure on government finances. Rate increases can also slow economic activity if businesses and households suddenly face higher financing costs.