Watch bond yields long enough, and you learn to expect surprises.
This time, however, it was one of the worst types of surprises: a terrorist-led atrocity.
The grim tragedy in Israel on Saturday blindsided bond yields, compelling global traders to reverse course and scramble into government bonds. Investors' intention, of course, was safety, so they fled to the financial world's #1 safe haven, U.S. Treasuries. That demand spilled over into government debt worldwide, pummeling yields (yields drop when bond prices rise).
The move in yields was forceful (see chart below):