Home-mortgage rates have surged to their highest level in more than three months, threatening prospects for quick rebounds in the housing market and consumer spending.

The average rate for 30-year fixed-rate loans jumped to 5.44% on Thursday, the highest level since early February, according to a survey by HSH Associates, a financial publisher. That was up from 5.29% Wednesday and 5.03% Tuesday.

Mortgage rates are being pushed up in part by a steep increase in yields on long-term Treasury bonds, which have a strong influence on the cost of home loans.

Wall Street Journal