• Japanese Finance Minister Satsuki Katayama and U.S. Treasury Secretary Scott Bessent reaffirmed their readiness to act against excessive yen weakness, keeping alive the possibility of another joint intervention.
  • The yen remains near a 40-year low despite a rare coordinated yen-buying operation on July 31, 2026, which may have cost Japan as much as $36.6 billion.
  • The Bank of Japan faces mounting pressure to tighten monetary policy as the weak currency fuels imported inflation and strains household budgets.

Japan and the United States are keeping the threat of another joint currency intervention on the table, as senior officials from both countries continue to signal that extreme yen weakness remains a shared concern.

In a series of exchanges this week, Japanese Finance Minister Satsuki Katayama and U.S. Treasury Secretary Scott Bessent underscored that orderly exchange-rate movements are vital for financial stability. While no new action was announced, their discussions reinforce a policy of close coordination that culminated in a rare joint yen-buying operation on July 31.

That intervention—the first coordinated U.S.-Japan currency action since 2011—aimed to arrest a slide that had pushed the yen to around ¥164 per dollar, its weakest level in roughly four decades. Japan’s Finance Ministry said the operation targeted “excessive volatility and disorderly market movements.”

On September 24, Katayama said the principles behind the July action “remain alive,” a deliberate warning to traders that authorities could step in again. The following day, she revealed that President Donald Trump had raised concerns about yen weakness in talks with Prime Minister Sanae Takaichi, who reportedly described an undervalued yen as problematic in principle. The issue has thus risen to the leader level, adding weight to official warnings.

A Delicate Balance

The yen’s depreciation has two opposing effects on Japan’s economy. For exporters and firms with large overseas earnings, a weaker currency inflates the yen value of foreign profits. But for importers, households, and businesses reliant on dollar-priced commodities, it raises costs for fuel, food, and materials—exacerbating inflation at a time when real incomes are already under pressure.

“What institutional investors like us are really focused on is regulatory stability,” said Andrea Valeri, Blackstone (BX)’s country chairman for Italy and chief investment officer for Blackstone Credit and Insurance’s private credit business in Europe and APAC, referencing a different context but highlighting the broader principle that policy predictability matters to markets. In Japan’s case, the stability of exchange-rate policy is now front and center.

Bessent has explicitly linked yen weakness to Japanese inflation, supporting decisive market and monetary measures to address what the U.S. calls a “substantial undervaluation.” His stance increases the pressure on the Bank of Japan to move away from its historically low interest rates, which have encouraged the yen carry trade—borrowing in yen to invest in higher-yielding assets.

Intervention Is Not a Cure-All

While intervention can disrupt speculative positioning, its lasting impact depends on whether monetary-policy differentials and capital flows also shift. The wide gap between U.S. and Japanese interest rates has made dollar assets more attractive and reinforced the yen’s decline. A more credible path toward higher Japanese rates would likely do more to support the currency than one-off operations.

The July intervention reportedly lifted the yen from its lows, and central-bank data cited by Reuters suggests Japan may have spent as much as $36.6 billion buying yen. Yet the currency remains vulnerable, and traders are watching for further warnings or action.

Markets will also focus on the Bank of Japan’s next policy decisions. Any sign of tightening could provide more durable support for the yen, but it would also risk destabilizing financial markets and undermining business confidence. For now, the joint U.S.-Japan stance raises the cost of betting on a one-way yen decline, even as the currency’s longer-term direction hinges on monetary policy, global risk appetite, and cross-border investment flows.

Correction: An earlier version of this article misstated the date of the joint intervention. It occurred on July 31, 2026, not July 31, 2025.