As you can see in the above chart, we have leveled off and even lost a bit in our upwards surge today.  Highs dinged at about 101-14 and we are currently trading around 101-09 on the 5.5% coupon.

Historically, we've broken through a ceiling, see below:

 The above char runs from late January through today.  As you can see, we've just crested the highs from the end of February, but we have another ceiling right above us to get through which is created by the formidable week at the end of January.  Are bonds upward bound or will they fall back to earth?  Spin the wheel and find out!

 
On a serious note, you always have to be ready for an immediate lock when we've risen this quickly (and really any time in the current climate).  Many lenders will require the MBS powerlifter to hold the bar for 3 seconds before giving him credit for the lift.  As soon as you see the price you want, the most cautious play is to take it.  If you can afford to play the market, this could be a good time.