Japanese Finance Minister Satsuki Katayama warned against speculative FX activity after yen briefly rose to below 156 per dollar.
The yen’s rally, from around 157.2 to sub‑156, reversed, settling near 157, following a $35 billion intervention that lifted it 3% last week.
Katayama referenced the Japan‑U.S. September joint statement limiting interventions to excess volatility, but gave no further details.