Yen volatility skew indicator signals intervention risk; short-squeeze momentum fades

Intervention risk facing USD/JPY is rising, with the options market showing increased demand for tools that protect against yen appreciation, signaling a possible tactical rebound in the yen rather than a sustained strengthening. Any intervention-driven yen appreciation is likely to be less persistent than the July move, because the positioning environment that previously fueled the yen's rally has largely returned to normal. The one-week risk reversal expanded to about 235 basis points, skewed toward yen call options, the highest premium in two weeks; the one-month volatility skew recovered to about 220 basis points from 200 basis points on September 11. Although one-month implied volatility has fallen back to around 7% to 8%, and the discount of option prices relative to realized volatility has reached its largest since early August, these changes still indicate that demand for upside hedging tools for the yen is increasing. This combination suggests that investors are paying closer attention to directional risk rather than broad market turmoil.