Japan's Top Currency Diplomat Mimura says they continue to stand ready on FX; declines to comment on if rate checks were conducted

Rhetoric of this kind from Japan's senior currency official follows a well-worn sequence: verbal readiness, then the conspicuous silence on rate checks, which in past episodes has itself been the tell, since confirmation calls to dealers have historically been the step immediately preceding actual yen-buying operations. Declining to comment on whether checks were conducted preserves ambiguity, a tactic officials have used deliberately to maximise the deterrent effect of positioning risk without committing reserves. The distinction that matters is between jawboning and action: verbal intervention has typically slowed the pace of yen weakness rather than reversed it, while actual operations have produced sharp but historically short-lived moves when they run counter to the underlying rate differential with the US. What has tended to determine effectiveness is whether the move in the yen is driven by speculative positioning, which intervention can flush, or by the widening policy gap, which it cannot. The follow-ons are further official commentary at escalating levels of seniority, any sign of coordinated discomfort, and the speed of the move itself, since Japanese officials have consistently framed their trigger as excessive volatility rather than any specific level.