First things first: the Fed cut its policy rate today, but that doesn't mean they cut mortgage rates.  Why?  Because they can't and they don't--especially not by a whopping 0.25% in a day (an amount that may be seen once or twice per decade when it comes to a single day's change in mortgage rates).  Case in point, mortgage rates for almost any lender are almost exactly where they were yesterday.

All that having been said, the Fed does SAY things that are important to the bond market that underlies rates.  That verbiage can always push mortgage rates in either direction regardless of the direction that the Fed moves its own policy rate.  In today's case, the Fed's verbiage was a bit friendlier than the market was prepared for.  As such, both stocks and bonds improved in the afternoon.   The average mortgage lender (as of 1pm ET, anyway) has not yet adjusted its mortgage rate offerings to reflect the bond market improvement.

Keep in mind, that bond market improvement isn't anywhere remotely close to 0.25% in terms of mortgage rates.  It won't even be 0.125%.  That means the average borrower isn't likely to see any change in quoted rates tomorrow morning, but in certain scenarios, the upfront costs could be slightly lower.  The important thing to understand is that it was not the Fed's rate cut that is affecting the bond market and the bond market hasn't moved enough to earn mortgage rates more than a token improvement.   It's also important to understand that if bonds weaken enough overnight, rates could actually be worse in the morning!