Japan’s Mimura warns of rapid yen moves as dollar nears 160

Japan's top currency diplomat, Atsushi Mimura, said on Thursday, November 12, Tokyo time, that recent yen moves had been too fast. He also said it was "too early to forget" this summer's interventions, as the dollar climbed back toward the 160-yen level that set off official action earlier this year.reuters.com

"I won't comment on the current exchange-rate level, but I believe recent currency moves have been excessively rapid," Mimura, the vice finance minister for international affairs, told reporters, according to Reuters. Bloomberg reported that he said he had "a strong impression that the currency moves over the past few days have been too fast." Bloomberg read the remarks as a sign that authorities stand ready to intervene again.bloomberg.com+1

Dollar at two-month high

USD/JPY rose early Thursday to its strongest level in more than two months. It was lifted by growing expectations that the Federal Reserve will raise interest rates, after hot US inflation data and hawkish comments from policymakers. investingLive noted that 10-year Treasury yields near 5% have outweighed strong data in Japan. Those figures include a 7.1% annual rise in October producer prices and expectations that the Bank of Japan will raise its 1.25% policy rate in December.investinglive.com+1

Memories of summer

Mimura's reference to the summer points to the yen-buying operations from late July into early August, including one carried out jointly with the United States. Finance Ministry data released on November 9 showed Tokyo bought a record ¥7.98 trillion on July 30, followed by ¥5.55 trillion and ¥1.87 trillion over the next days. That brought the total to about ¥15.4 trillion. The July 31 operation was the first coordinated US-Japan action to support the yen since 1998.finance.yahoo.com+1

After the joint action was confirmed, US Treasury Secretary Scott Bessent said Washington "will not hesitate to participate in further joint intervention". Japan had also stepped in around late April and early May, after the dollar rose above 160.thedailystar.net+1

Watching the wording

Traders are now watching whether Tokyo's language moves beyond describing moves as "rapid" to phrases such as "decisive action." In 2026, wording like that came before both rounds of intervention. Even so, the summer operations did not give the yen a lasting floor. In early October, BNY argued that the joint intervention "buys time, not credibility." That leaves officials trying to slow a slide driven mainly by the gap between US and Japanese interest rates.bny.com+1