Today was largely the story of troublingly weak econ data prompting an rally to the best levels of the day for bond markets.   The biggest move came in response to European PMI data overnight.  France, Germany, and Eurozone PMIs were almost universally weaker with Germany's manufacturing sector defying already low expectations.  European bond yields tanked in response and US yields followed.

The rally extended just a bit after mixed US PMI data at 9:45am (weaker services sector, but manufacturing held its ground).  Shortly thereafter, bonds began a steady selling spree that brought them back to unchanged on the day and ultimately into negative territory.

Several Fed speakers were hitting the wires at various points throughout the day, but generally not adding anything new to last week's thesis of "data dependence" in the coming weeks.

In technical terms, it's worth noting that 10yr yields bounced rather obviously on the 1.67% pivot point (a rather obvious "floor" based on high volume lows from September 12th and the mega rally's initial resistance that showed up on August 6th) and that there was no overt provocation for the bounce apart from technicals/momentum.