While "whatever it takes to stay sideways" makes it sound like some sort of passionate goal, it's really just a byproduct of the season (or a simple objective math equation).  Specifically, bonds have either been rallying if yields get too high or selling if yields get too low.  Everyone gives up their more passionate goals and abstains from opportunistic trading.  Then, everyone can get what they want/need here at the end of 2015.  If some traders were intent on deviating from the unspoken consensus, they'd run a higher-than-normal risk of failing. 

(For what it's worth, the path of least resistance isn't always "sideways" at the end of the year, but it certainly is this year.)

Economic data was deceptively unimportant today.  At first glance, it looked like Durable Goods (which beat its forecast at the headline level 0.0 vs -0.6) was responsible for bond market weakness.  A deeper look reveals capital expenditures (a component of the report) fell 0.4 percent vs a median forecast for a -0.1 percent decline.  The same metric was also revised lower for last month from 1.3 to 0.6.  That's a much bigger story for bond markets, and one that would suggest a move in the opposite direction. 

The data can further be dismissed as a market mover when we look at the trading leading up to it.  Not only were bonds steadily weaker overnight, but they kicked into a slightly higher gear of selling at the 8:20am CME open.  This acts like an unveiling of previously unknown trading positions because certain traders cannot trade any earlier.

Bond markets close early tomorrow (2pm ET), but are clearly already unofficially closed.

MBS Pricing Snapshot
Pricing shown below is delayed, please note the timestamp at the bottom. Real time pricing is available via MBS Live.
MBS
FNMA 3.0
99-24 : -0-04
FNMA 3.5
102-29 : -0-03
FNMA 4.0
105-17 : -0-02
Treasuries
2 YR
0.9890 : +0.0120
10 YR
2.2590 : +0.0200
30 YR
2.9900 : +0.0260
Pricing as of 12/23/15 5:32PMEST
Today's Reprice Alerts and Updates
A recap of Alerts and Updates provided to MBS Live subscribers.
10:07AM  :  Markets Largely Ignoring Data in Favor of Tradeflows
MBS Live Chat Highlights
A recap of featured comments from the Live Discussion on the MBS Live Dashboard.
Matthew Graham  :  "if any of you are reading this and completely don't understanding, don't worry! I don't even understand what I'm saying. I think it all means that the Fed as a big warehouse full of sponges that soak up extra cash and wring it back out every day, and they've only had to use a small percentage of those sponges to keep things as moist as they want."
Hugh W. Page  :  "It's amazing the tinkering going on by the Fed. Take away the Cap on Rev Repos and increase paid on reserves. Reinvest principal payoffs on tsys and mbs, and I'm sure I'm leaving something out. Amazing really."
Matthew Graham  :  "Either way, they have plenty of headroom because RRP is only limited by their total open market account holdings"
Hugh W. Page  :  "With loan demand down I guess banks got an early xmas present :)"
Matthew Graham  :  "so far, the amount of $ in RRP required to achieve the target zone has been FAR lower than the buzz would suggest"
Matthew Graham  :  "Mopping up at the lower bound with the reverse repurchases (RRP) and at the upper bound (just for dealers) with IOER (interest on excess reserves). Too different rates because the RRP is available to more accounts."
Matthew Graham  :  "Yes HP."
Hugh W. Page  :  "So, MG, Fed also raised the interest rate paid on Reserves and Excess Reserves by 25 bps to 50 bps. Would the main purpose of such a move be to keep the money supply tighter and thus better ability to control the effectove FF rate?"