Mortgage rates move lower again today.  Combined with yesterday's drop, the improvement has been significant for top tier rate quotes in the lower range of available rates.  What does that mean, exactly?

A rate quote isn't simply a rate.  That's only one side of the equation.  The other side is the upfront cost.  Generally speaking (and there are exceptions) the higher the rate, the lower the upfront cost, all other things being equal.  Depending on movement in the bond market, certain mortgage rates can see varying amounts of change in their associated upfront costs.  At the moment, it's the lowest available rates that have seen the biggest benefit. 

For instance, there's not much difference between yesterday and today's quotes for conventional 30yr fixed rates of 3.25% and above, but there is substantial improvement for rates of 3.125% and below.  By the time we consider yesterday's gains, we're looking at an effective rate drop of .125%. 

These claims run counter to the prevailing news coverage of this week's mortgage rate situation.  Reason being: the prevailing coverage (referring to the average news article on mortgage rates from any major media outlet--possibly even your evening news, if you're into that sort of thing) relies on Freddie Mac's weekly rate survey for one big mortgage rate article each week.  But Freddie's survey doesn't capture the changes that occur in the 2nd half of any given week.  As such, the survey missed out on this week's best improvement and consequently logged rates that were just slightly higher than last week's.