MBS prices have added on 3-4 ticks from this AM's already higher levels.  The 4.5 is up 9 ticks overall to 102-01.  That's right, 102 as in ONE ZERO TWO.  MBS closed as high as 101-31 on May 17th just before Black Wednesday hit...

As we mentioned last week, at that time, treasuries were closer to 2% than 3% in the 10yr.  An although the 10yr has rallied 20 ticks so far today, dropping the yield 7bps, the 2% handle is but a faded memory considering the current yield of 3.351. 

You'll notice in the chart below that both MBS and tsy's (and stocks for that matter) are showing some early signs of fizzle as none of the 3 appear willing to extend beyond respective resistance today.  That centers on 102-00 for MBS, 1110 in the S&P and 3.35 in the 10yr

Watching and waiting is about all there is at the moment...  If a deal is float biased, you'd be waiting for the benefits of this rally to hit rate sheets, and then potentially watch for excessive weakness as you consider the overnight float.  Lock-biased portions of the pipeline would likely be in the exact same boat, except resolved to cash in on the later day gains, whatever they might be, and without being exposed to the risk of lower prices tomorrow morning...