Weak personal spending and a higher savings ratio didn't hurt, particularly after an ISM plunge to 50.5 from 53.9, while a 1.7% jump in construction spending and weak auto sales were ignored. There really wasn't one particularly compelling trigger for the shift in sentiment, though fragile sentiment was highlighted by the weak pretext of a U.S. spy/fighter plane incident over North Korea. This turned out to be a red herring (a stale story from earlier in the weekend), though U.S. officials confirmed it.
Otherwise, dealers said there was no major block or curve trades over the day, though vol on benchmark 10-year notes was sold early before recovering part way. The June bond closed up 2/32 at 114-17, well up from lows of 114-05. The two-year note and 30-year bond spread drifted around an unchanged +315 basis points before a late three basis-point sprint to +318 basis points.