• 2 things: tomorrow's FOMC Minutes and Today's Dell corporate bond
• Both put pressure on bond markets
• majority of weakness was in afternoon and focused on shorter-term debt
• That's how we know it was more about Fed fear

Bond markets were doing a fair enough job of fighting off the implications of this morning's "as-expected" Consumer Price Index data, which continued to operate in the danger zone as far as Fed rate hike implications are concerned (Core CPI of 2.1% year-over-year).  Naturally, it didn't do too much damage considering it came in in-line with expectations. 

More damaging was the slow-motion panic that set in over tomorrow's FOMC Minutes.  The fact that we're only getting the Minutes from the late April Fed Meeting keeps the volatility in check, but investors were nonetheless concerned that the more detailed account of that meeting might show a Fed that was closer to hiking rates than the official announcement managed to convey.  The fact that short term yields lost the most ground today supports that conclusion.  

The big corporate bond deal from Dell also added pressure, but it was in the form of late day selling needs hitting an illiquid and already anxious market.  That made for quick losses heading into the close.  It likely wouldn't have been as bad as it was if the Fed wasn't coming up tomorrow and if market participants weren't digesting Fed speeches that seemed to support the rate hike ideology.  

Even then, the losses weren't too earth-shattering in terms of 10yr yields, which only rose 1.5bps to 1.772.  MBS lost a little more ground, given that they're slightly shorter duration bonds by nature (and short duration got hit the hardest).  For reference, 2yr yields rose 4.5bps.