Which exchange rate moves matter and which interest rates are important?

Even when talking about U.S. interest rates (Treasury yields), the moves differ for 2-year, 5-year, 10-year, and 30-year bonds. They do not move in parallel.

The fluctuations in the yields on 10-year and 30-year bonds, which reflect economic cycles experienced over a long period, are relatively small. The 2-year bond, since the Fed has indicated it will not change the policy rate until next summer (that is, for roughly the next year), represents a shorter period for reflecting policy rate changes. In that sense, the 5-year rate is most likely to reflect near-term monetary policy and inflation concerns.

Typically, the dollar/yen has been determined by the U.S.-Japan 10-year yield spread, and the euro/dollar by the German-U.S. 2-year yield spread, but