Asian currencies forked three ways on October 13. USD/JPY closed at 158.24, down 0.227, a mild yen firming; USD/KRW closed at 1,342.3, up 0.5996, the won kept weakening; USD/CNY closed at 6.6969, up 0.0433, a slight RMB softness. With three rates moving apart, a Northeast Asian refiner's dollar book cannot be run off a single FX assumption.

A firmer yen lowers the dollar-denominated feedstock cost for Japanese plants, so JXTG and Idemitsu spend less in local currency on imported crude. A weaker won does the opposite: SK and GS pay more for dollar procurement and must pass it through via higher product export prices.

The slight RMB softness cuts both ways for SNSUC. Imported landed cost edges up, but refiner clients holding dollar receivables get better conversion, so we can concede a little less FX discount in entrepot pricing.

On the desk we trimmed the yen exposure, added a hedge on the won, and left the RMB to play a pre-holiday rebound. Under this three-way split, a single-currency view quietly loses money.