Summary:
Japan’s intervention warning gave the yen a modest lift
USD/JPY slipped toward 157.25 from highs near 157.75
Officials flagged concern over “one-sided and sharp” moves
Verbal intervention slowing momentum, not reversing trend
AUD/JPY still supported by yield differentials
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A renewed warning from Japanese officials about the risk of currency intervention has given the yen a modest lift at the start of the week. The move followed comments from Japan’s top currency diplomat, Atsushi Mimura, which pushed USD/JPY about half a big figure lower from earlier highs near 157.75 as I update, to around 157.25.
Mimura said on Monday that authorities are “concerned” about recent foreign-exchange moves, describing them as “one-sided and sharp,” and warned that officials would take “appropriate actions” against excessive volatility. The language was familiar, but the timing, coming so soon after last week’s central bank meeting, has been enough to nudge the market toward trimming short-yen positions.
The remarks followed similar comments late last week from Finance Minister Satsuki Katayama, who also warned that Tokyo would respond appropriately to excessive and speculative yen moves. Together, the statements underline growing discomfort in Tokyo over the pace of yen weakness, particularly given the impact on import prices and household living costs.
While the move in USD/JPY has so far been measured rather than dramatic, it reinforces the sense that official tolerance for renewed yen declines is limited, especially when moves appear disorderly. For now, verbal intervention appears to be doing just enough to slow momentum, even if it has not yet triggered a broader reversal.
Elsewhere in FX, I note earlier commentary from Commonwealth Bank of Australia on AUD/JPY, which continues to find fundamental support from solid risk sentiment and, more importantly, widening interest-rate differentials between Australian and Japanese 10-year government bond yields. That yield gap remains a powerful structural driver for the cross.
CBA’s forecast has AUD/JPY rising to 109 by March 2026, highlighting that while intervention risk may periodically cap yen weakness, broader yield dynamics continue to favour higher AUD/JPY levels over the medium term.
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Atsushi Mimura is Japan’s vice finance minister for international affairs — the country’s top currency diplomat — and the official with day-to-day responsibility for overseeing foreign-exchange policy. In practice, Mimura is the key decision-maker on whether Japan intervenes in the FX market, acting under the authority of the finance minister and in coordination with the Bank of Japan, which executes intervention operations on his instruction. He monitors market conditions closely, assesses whether yen moves are excessive, disorderly or driven by speculation, and delivers the government’s verbal warnings that often precede action. When intervention is authorised, Mimura formally directs the BOJ to enter the market, typically through yen-buying operations aimed at stabilising sharp or one-sided moves rather than targeting specific exchange-rate levels.
