mortgage rates shot up this week ahead of the upcoming release of inflation statistics according to housingfinance agency freddie mac in the week ending thursday the average rate on a 30year fixedrate mortgage edged higher to 523 from 509 last week a year ago this week the average rate was 296 average 15year rates were 438 up from 432 a week ago and 223 a year ago the average rate on a fiveyear treasuryindexed hybrid adjustablerate mortgage or arm was 412 up from 404 last week a year ago the fiveyear arm averaged 223 after little movement the last few weeks mortgage rates rose again on the back of increased economic activity and incoming inflation data said sam khater freddie macs chief economist the housing market is incredibly ratesensitive so as mortgage rates increase suddenly demand again is pulling back the material decline in purchase activity combined with the rising supply of homes for sale will cause a deceleration in price growth to more normal levels providing some relief for buyers still interested in purchasing a home