Let's clear one thing up before we begin.  Freddie Mac, MBA, and Ellie Mae all noted new 4-year highs in mortgage rates this week.  They are all technically wrong.  This has to do with the way their data is collected and/or averaged.  And while I have no doubt that they are accurately conveying the results of their data collection efforts according to their methodology, there is a more accurate way to do things.  Specifically, we can track actual lenders' rate sheets every day. 

Even if we take an average of that daily data, we still find that rates aren't quite back to 4-year highs just yet.  Depending on the lender, these occurred on one of the days near the end of February.  In fact, some lenders' rates from March 21st are still higher than today's.  Are we talking about very big differences between now and then?  Not at all!  But if we're going to talk about rates hitting 4-year highs, we might as well be precise about it.

One thing everyone can agree on is that today's rates are higher than yesterday's, which in turn, were higher than Wednesday's.  The lion's share of that move higher happened yesterday, but today's underlying bond market movement suggests there's a bit more pain yet to be priced-in to the average lender's mortgage rate sheets.  If bonds deteriorate further this afternoon, some lenders could adjust their rate sheets today.  Those who don't will will simply be starting next week at a disadvantage.  In other words, even if bonds are unchanged on Monday morning, mortgage lenders would likely need to begin the day with higher rates compared to today's.