Dollar vs Japanese yen — uniquely sensitive to the US-Japan rate differential.
Highly sensitive to the Fed-BoJ spread and US Treasury yields. The yen is also a safe-haven, so flips can be violent on risk-off days.
Borrow yen at near-zero rates and buy higher-yielding assets. The strategy works until the yen sharply unwinds.
When USD/JPY moves too far too fast, Japan's Ministry of Finance can sell USD reserves to buy JPY. Watch for verbal warnings first.
0.01 (because it's a JPY pair). 1 pip on 1 lot = ~$6.70 in USD terms.