Goldman Sachs Chief Japan Economist was reported by Bloomberg, as saying that the BoJ and the Japanese government have "very limited" policy options for reining in the Yen appreciation
“Most likely to take a wait-and-see stance until the latest round of gains come to an end.
The risk for BOJ is that the yen's gains put strong downward pressure on 10-year government bond yields.
Fixed-rate buying operations not effective when rates are falling.
If the BOJ wants to prevent a further decline, it would need to reduce JGB purchase amounts, but that could lead to further Yen appreciation.
Conversely, precisely because of this risk, the BOJ is likely to allow the 10-year rates to remain at a low level for the time being.
Extremely low feasibility of FX intervention.”