Monday's yen surge is unlikely to reflect fresh official FX buying; position
rebalancing appears the primary driver. BOJ intervention typically drains yen
liquidity and produces funding gaps that far exceed market forecasts; earlier
suspected intervention showed that pattern. This time the BOJ's expected funding
shortfall was ¥3.38 trillion versus prior market estimates of ¥2.32–2.60
trillion — a difference of about ¥0.8–1.06 trillion, too small to signal clear
intervention and more consistent with routine flows or fiscal operations. BOJ
money-market data suggest that when the funding gap does not materially
overshoot forecasts, exchange-rate moves are likelier driven by market
positioning than official buying. Markets have shifted from questioning whether
there was intervention to fearing further action: confirmation of prior
U.S.-Japan coordination can reduce USD/JPY long leverage and prompt yen short
covering even without new purchases. Key trigger to watch is whether USD/JPY
again approaches 160; that would increase the probability of verbal warnings
being escalated to actual intervention.