We knew we'd have to deal with it at some point, and now we have to wonder if it's already here: the coronavirus bounce.  

Why did we know it was coming?

Nothing too complicated here...  The recent rate rally was/is unequivocally driven by a big, uncertain, temporary factor that has required markets to position defensively for stuff that probably won't happen.  Once it looks like the most dire coronavirus scenarios have been ruled out, we'd expect markets to give back the premiums they'd been paying for increased uncertainty.  In other words, bond yields should bounce.

Why are we wondering if it's already here?

This one is simple too.  The rate rally has been sharp.  It's lasted a few weeks.  It's taken rates back in the vicinity of recent long term lows.  It's made technical measurements of momentum look ripe for correction.  And now, finally, today's weakness arrived at a pretty ideal time and in a pretty ideal amount to fill the role of "day 1" of such a correction.

All of the above having been said, days 2, 3, and 4 will be more important.  Coronavirus news can certainly still shift and global economic data can certainly still have a say.  That's not to suggest complacency as much as it is intended to acknowledge the ongoing potential for volatility--at least until the next trend is established.