Freddie Mac released its weekly update on national mortgage rates Thursday morning, revealing that a pullback in rates had already begun, even before the Fed surprised watchers on Wednesday by not beginning to dial back bond purchases.

Both 30-year fixed-rate mortgages (FRMs) and 15-year FRMs experienced declining rates in the past week, with 30-year loans dropping seven basis points to land at 4.50%, and 15-year loans shedding five b.p. to end up at 3.54%.

Among adjustable-rate mortgage (ARMs), 5/1 ARMs fell 11 basis points to 3.11%. One-year ARMs dipped two b.p. to 2.65%.

Commenting on the numbers, Freddie Mac Vice President and Chief Economist Frank Nothaft said in a statement that "a weakening economic recovery" was largely to blame for the falling rates. He noted industrial production, employment growth, and retail sales numbers all lagging estimates lately, and consumer sentiment falling for its second straight month in September to the lowest reading since April.

The Federal Reserve's decision to continue buying $85 billion in mortgage-backed securities every month could well accelerate the rate declines. The Fed justified its decision by saying the economy still needs stimulus support. It will continue its efforts to keep rates low, stimulate interest in taking out loans, and thereby, hopefully, induce the economy to grow faster.

Mortgage rates have increased more than one percentage point since early May when speculation about Fed tapering began. They remain near a two-year high.