Consolidating, biding time, coiling, storing energy, etc...  Over the years on MBS Live and elsewhere, you may have come into several iterations of this same concept.  It occurs when trading levels (in bonds, stocks, or anything else) had been moving in one direction or the other and then settle into a sideways or consolidating range.

Remember cars with manual transmissions?  Remember learning how to drive them or helping others to do so?  These sideways, consolidative weeks/months in financial markets are like the time between shifts for someone who is new to manual transmissions.  There's more time than there needs to be where power is disengaged from the wheels.  Once the driver starts letting off the clutch, there's more jerkiness than normal.  The important point is that the period of neutrality merely sets the stage for acceleration or deceleration.

Bonds are in neutral:

Train your eye to the yellow wavy lines at the top of the chart.  They're as flat as they've been in a long time.  Only early 2017 even comes close.  Early 2017 also serves as a good example of the aforementioned "jerkiness" because it looked like the next move was going to be toward higher rates whereas the actual momentum ended up being friendly.

In the current case, we're certainly meant to believe the tax bill will tell bonds whether to upshift or downshift in the short term.  While I do think there's more short-term weakness in store if the bill passes, the long-term implication would be toward even lower rates, given that most rich folks, traders, and politicians fail to appreciate the extent to which wealth inequality prevents growth and inflation.

These bigger-picture considerations are almost exclusive market movers right now (hence the flatness, because we're waiting on tax bill news).  That also means economic data is 2nd fiddle (is there a 3rd or 4th fiddle?  Because that would be even more accurate).