US mortgage rates have plunged to a 50-year low, sparking a surge in refinancing that is helping growing numbers of homeowners reduce their borrowing costs, the FT reports. Freddie Mac, the quasi-government entity that buys and insures mortgages, said on Thursday that an average US 30-year fixed-rate mortgage had dropped to 4.15 per cent, down from 4.32 per cent last week. The average in effect mortgage rate is 5.3 per cent, according to the Bureau of Economic Analysis, suggesting more borrowers could benefit. Homeowners are looking to take advantage of ultra-low US Treasury yields, which are used to price mortgages, to apply for refinancing. Data from the Mortgage Bankers Association show a 4.1 per cent increase in applications last week, with the sharp upward trend starting at the end of July. “It’s spurring a lot of people who were really fence-sitting, people who refinanced last year at 4.85 per cent,” said Daniel Kramer, a mortgage broker at United Mortgage Services, servicing affluent areas of New Jersey, New York and Connecticut. Read more