"For no apparent reason" is a bit of an overstatement.  There are several plausible reasons that bonds could be rallying as well as they are at the moment--not the least of which being the extent to which they sold off at the end of 2016.  The rationale for the 2016 sell-off was somewhat tenuous, given its size.  MBS Live has been steadfast in saying that we were not seeing a 1:1 ratio of justification and market movement.

Reason being: the justification in this case was the "growth and inflation" potential associated with the new administration combined with the fact that any major bounce in yields right now might make it look like a decades-long bullish trend was coming to an end.  Even traders who didn't believe in that narrative were best-served by pushing rates higher to set up better entry points for their buying goals.  I've been sounding the alarm on that "jawboning trade" for several months now and it finally seems to be turning around.

Just today we had another in a string of recent articles pushing back on the "OMG HIGHER RATES!!" narrative.  Additionally, one of the bond kings (Gundlach) was out this afternoon saying that 10yr yields will move to 2.25% because Europe is a mess.  I might take that a step further and say that any additional positivity could simply be driven by US markets beginning to price in a more sober near-term future--one in which the new administration isn't easily able to wave a magic wand and create 3% GDP and push the pace of inflation.

Could it be that new Treasury Secretary Mnuchin merely had to say (on Thursday) that 3% growth wouldn't happen until the end of 2018 and that policies would take time to be effective for markets to wake up and start trading like it?  There's a lot more to consider today and the attached video will be a good resource if you want to explore that rabbit hole.