Last week, Fed Chairman Ben Bernanke pronounced himself "a little puzzled" by how much Treasury yields had risen in the past month. He must be positively flummoxed by now.

The 10-year Treasury note finished Monday yielding 2.55%. That is up from 2.18% last Tuesday, before Bernanke said that the Fed is looking to start reducing its monthly bond purchases in the fall, aiming to end them by mid-2014. On May 21, the day before he first suggested the Fed might start scaling back the bond-buying programme, the yield was 1.94%.