UMBS 2.5 coupons are down 3/8ths of a point from the highs, but what does that even mean in this environment?  Do you even have rate sheets yet?  If you do, did you get a reprice for the better or significantly stronger pricing versus Friday afternoon?  

During more normal times for MBS vs mortgage rate movement, a 3/8ths drop from the highs would almost always result in negative reprices.  Few lenders remain in that mindset, and if you're floating with one of them, you likely know who they are based on past precedent. 

Even then, a much better indication of reprice risk is the general level of aggression on any given rate sheet, both compared to peers and to the same lender's pricing from the previous session.  In other words, if today's sheet is significantly better than Friday's and near the front of the pack as far as you can tell, chances are that lock volume will be high and that it's only a matter of time before a pipeline control reprice, regardless of MBS levels.