US mortgage rates rose for the first time in five weeks, thwarting a budding recovery in housing demand and abruptly halting a recent flurry of home refinancing.

The contract rate on a 30-year mortgage climbed 12 basis points to 6.46% in the week ended Sept. 26, according to Mortgage Bankers Association data released Wednesday. Adjustable-rate and 15-year fixed mortgages also increased last week.

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The group’s measure of refinancing tumbled nearly 21%, the largest retreat this year, after reaching the highest level since early 2022. The index of home-purchase applications slipped 1%.

The rebound in borrowing costs illustrates an elevated level of interest-rate sensitivity for a housing market that has recently showed signs of emerging from a multi-year slump. A sustained decline in mortgage rates could help lure prospective buyers, who have been sidelined by a lack of affordability, to purchase a home.

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The MBA’s overall measure of mortgage activity, which includes home purchases and refinancing, declined last week by the most since April. 

The MBA survey, which has been conducted weekly since 1990, uses responses from mortgage bankers, commercial banks and thrifts. The data cover more than 75% of all retail residential mortgage applications in the US.