Mortgage rates were pushed down by rising concerns about the omicron coronavirus variant heading into the holiday.

According to the latest data released Thursday by Freddie Mac, the 30-year fixed-rate average dropped to 3.05% with an average 0.7 point. (A point is a fee paid to a lender equal to 1% of the loan amount. It is in addition to the interest rate.) It was 3.12% a week ago and 2.66% a year ago.

Freddie Mac, the federally chartered mortgage investor, aggregates rates from around 80 lenders across the country to come up with weekly national averages. The survey is based on home purchase mortgages. Rates for refinances may be different. It uses rates for high-quality borrowers with strong credit scores and large down payments. Because of the criteria, these rates are not available to every borrower.

The 15-year fixed-rate average fell to 2.3% with an average 0.7 point. It was 2.34% a week ago and 2.19% a year ago. The five-year adjustable rate average sank to 2.37% with an average 0.4 point. It was 2.45% a week ago and 2.79% a year ago.

"The market volatility resulting from the covid-19 omicron variant is causing mortgage rates to decrease," Sam Khater, Freddie Mac's chief economist, said in a statement.

Investors are watching news about the omicron variant closely, worried about its potential to inflict economic damage in the form of shutdowns. Except for Dec. 8 when it closed at 1.52%, the yield on the 10-year Treasury has remained below 1.5% the entire month. It closed at 1.46% on Wednesday.

The movement of the 10-year Treasury is often one of the best indicators of where mortgage rates are headed, though that has been less the case recently because of the Federal Reserve's involvement in the market. When bond prices rise and yields fall, rates tend to fall.

"With many bond traders off for the holiday, it's hard to get a sense as to how the bond market will see the increasing covid cases from the omicron variant," said Michael Becker, branch manager at Sierra Pacific Mortgage. "It may take a couple weeks for us to get a sense of how the increase in cases will affect the economy."

The National Association of Realtors released its sales of existing homes data for November this week. It showed sales rose last month, up 1.9% from October.

"Buyers continue to close contracts for both new and existing homes, hurrying to lock in low mortgage rates before they rise," said George Ratiu, an economist at Realtor.com. "The combination of rising inflation and the Federal Reserve's accelerated tapering of mortgage-backed securities purchases is expected to push interest rates higher in 2022, trimming many buyers' budgets."

Bankrate.com, which puts out a weekly mortgage rate trend index, found nearly two-thirds of the experts it surveyed expect rates to stay the same in the coming week.

"Uncertainty about covid dominates the news and investor choices about where to put their money," said Dick Lepre, senior loan officer at RPM Mortgage. "People are starting to realize that no one has the faintest clue as to when this disease and its seeming never-ending trail of variants will end. Uncertainty drives money to the safety of fixed-income securities and keeps mortgage rates low despite high inflation numbers."

Black Knight, a mortgage data and technology company, released its mortgage performance data on Thursday. Overall mortgage delinquency fell 4.1% last month, down 43% year-over-year. The number of borrowers who are 30 or more days past due but not in foreclosure fell to 1.9 million for the first time since the initial run-up at the start of the pandemic. Serious delinquencies - those mortgages more than 90 days past due - dropped by 80,000.

Mortgage applications were down last week. According to the latest data from the Mortgage Bankers Association, the market composite index - a measure of total loan application volume - decreased 0.6% from a week earlier. The purchase index fell 3%, while the refinance index rose 2%. The refinance share of mortgage activity accounted for 65.2% of applications.

"Mortgage applications fell last week, driven by a 3% decline in purchase applications," Joel Kan, an MBA economist, said in a statement. "Both conventional and government purchase applications were down, while the average purchase loan increased for the second straight week to $416,200 - the second-highest amount ever. The elevated loan size is an indication that activity is more on the higher end of the market."