Can't the yen appreciate? Japan's Foreign Exchange Minister cites IMF rules: there is no limit on the number of currency interventions.

Japanese Ministry of Finance Financial Director Atsushi Mimura—commonly known in the market as the “Chief Forex Official”—made a clear statement at a press conference, directly referencing the International Monetary Fund (IMF): the rules never explicitly specify a cap on the number of interventions. Once he finished speaking, forex traders immediately read between the lines: Japanese authorities still retain the legal basis to intervene at any time, and the yen’s sharp rise to the 155 level on Wednesday, May 6, was merely another round of betting and counter-betting, a halftime break.

What exactly did Atsushi Mimura say?

Atsushi Mimura explicitly told reporters that the IMF’s classification of “free-floating exchange rates” does not impose restrictions on how frequently countries can intervene in the foreign exchange market. He also emphasized that the government will continue to monitor exchange rate movements with a “high sense of urgency,” scanning various markets for possible countermeasures.

Regarding the two issues most concerning the market, Mimura chose to remain silent: first, whether there is an implicit safety net for the yen; second, the upcoming visit of U.S. Treasury Secretary Scott Bessent. He refused to comment on the former and said nothing about the latter, only reiterating that speculative activities in the foreign exchange market “are still ongoing.”

It is worth noting that Mimura did not deny recent market fluctuations. The yen’s sharp rise on May 6 was interpreted by outsiders as another signal of intervention—“action replacing words”—by the Ministry of Finance, but Mimura explicitly refused to comment on this volatility.

Bloomberg’s calculation of IMF’s account: only 2 rounds left before November

Mimura is correct—there is indeed no explicit “limit on the number of interventions” in the IMF rules. However, Bloomberg analyzed the thresholds for IMF’s classification of “free-floating exchange rates” and pointed out that once a country exceeds three interventions within six months, its “free-floating” status could be questioned. The calculation considers that “consecutive interventions within three days count as one operation.”

Looking at recent intervention records from the Japanese Ministry of Finance, the numbers are not optimistic: on April 30, May 2, and May 4, the government intervened three times, totaling about 54 billion USD. The largest single-day intervention was on April 30, with approximately 34.5 billion USD, successfully pushing the yen back from 160 to around 155; the effects of the subsequent two interventions diminished, with market rebounds noticeably smaller.

According to Bloomberg’s framework, from early May, Japan has used up three intervention rounds within a six-month window, which will end in November, leaving only two more intervention opportunities. In other words, while Mimura emphasized “IMF has no cap” during the press conference—technically true—if Japan intervenes two more times, its classification as a “free-floating” currency could be at risk of reclassification by the IMF—that’s the real hidden ceiling.

Bessent visits Japan next week—how much longer can the yen hold?

Diplomatic relations are also heating up. U.S. Treasury Secretary Scott Bessent is scheduled to visit Japan next week, where he will meet with Prime Minister Sanae Takaichi. Topics include trade, exchange rates, and how to curb speculative selling pressure on the yen.

Although Mimura refused to comment on Bessent’s visit, he revealed that he maintains daily contact with U.S. officials, and that the U.S. side “fully understands” Japan’s approach and actions. This statement carries weight: if Japan and the U.S. have already reached a tacit understanding on intervention, the cost of betting against the yen is no longer just about opposing the Japanese Ministry of Finance but against a joint front backed by the United States.

The current market question is no longer “Does Japan dare to intervene?” but “How many rounds are left?” IMF’s account suggests only two rounds before November, while Mimura’s attitude indicates readiness to act at any time. Bessent’s upcoming visit hints that bilateral coordination may be taking shape. The next move for the yen might only become clear at the moment Bessent lands in Tokyo.

This article is based on a report from Jinsei Finance published on May 7, 2026, summarizing Mimura’s statements, with background context from Bloomberg and Japan Times, compiled by Dongqu Dongqu.