BoJ conducted a "rate check" with market participants late Friday, signaling potential preparation for currency intervention, reports Nikkei

Past episodes have followed a fairly consistent escalation ladder: verbal warnings from finance officials, then rate checks, then spot orders, and the check itself has on previous occasions been enough to trigger sharp short covering in the yen even without a confirmed order. The operative distinction is between a one-off check used as a warning and checks that immediately precede real flows; the latter tend to come when moves are disorderly and one-sided rather than at any fixed level, with authorities consistently framing speed of depreciation as the trigger. Intervention of this kind has historically bought time rather than reversed trends when the underlying rate differential remains wide, so the pattern has been an initial knee-jerk yen rally followed by drift back toward the prior trajectory. Worth watching are confirmation or denial from the MoF, the size of any follow-on orders reported through dealer channels, and whether the dollar side of the pair, rather than yen-specific factors, is doing the work. Timing late in the week and into thinner liquidity has also been a recurring feature of past operations.