Surprisingly and refreshingly, today's ISM Manufacturing data has been a clear source of motivation for trading activity today.  After it came out at the weakest levels since June, bonds rallied significantly and stocks fell sharply.  There's a chance that investors are sensing a negative shift in economic momentum as the ISM numbers were unable to break above an index value of 60.0, despite coming close in 3 out of the past 5 months.  Indeed, 59.3 is the highest reading since June 2004, but there have been 14 reports at 57.5 or higher.

15 minutes before the ISM data, the less-highly-regarding Markit PMI data offered a potential early indication of weakness in the manufacturing sector.  It came in at the lowest levels since January 2014, and bond markets seemed to react to that.  This is significant because Markit PMI doesn't frequently motivate much of a reaction.

Before that, the morning's only noticeable market mover was a big block trade in Treasury futures.  That served to stem overnight losses and kick off the day's first sign of positive momentum.  It got bonds back to neutral territory before the manufacturing data pushed them well into positive territory.  10yr yields are over 6bps lower at 2.107 and Fannie 3.0s are nearly half a point higher than Wednesday's latest levels.