Fixed mortgage rates sank to their lowest level in three years on fears about the economic impact of the coronavirus.

According to the latest data released Thursday by Freddie Mac, the 30-year fixed-rate average tumbled to 3.45 percent with an average 0.7 point. (Points are fees paid to a lender equal to 1 percent of the loan amount and are in addition to the interest rate.) It was 3.51 a week ago and 4.41 percent a year ago.

The 30-year fixed rate hasn’t been this low since October 2016. But it remains well above its all-time low of 3.31 percent set in 2012.

The 15-year fixed-rate average fell below 3 percent for the first time since November 2016, dropping to 2.97 percent with an average 0.7 point. It was 3 percent a week ago and 3.84 percent a year ago. The five-year adjustable rate average rose to 3.32 percent with an average 0.2 point. It was 3.24 percent a week ago and 3.91 percent a year ago.

Rates’ three-week swoon has been driven primarily by concerns over a potential slowdown in economic growth from the coronavirus outbreak. But now that those fears have started to abate, mortgage rates are expected to go back up.

“Rates officially touched their lowest levels in three years late last week, but key readings on the manufacturing and services industries, as well as private payrolls data, bested industry expectations and boosted investor sentiment on Wednesday,” said Matthew Speakman, a Zillow economist. “But, much like last week, the central story that drove bond prices, and thus mortgage rates, was the ongoing developments around the coronavirus outbreak in China. Optimism has risen in recent days after rumors of a medication and news that China’s central bank could cut its key lending rates in order to support economic growth that has languished as a result of the outbreak.”

The yield on the 10-year Treasury rebounded after nose-diving to 1.51 percent Friday. In less than a month, it had fallen from 1.88 percent, mainly on fears surrounding the coronavirus outbreak. But by Wednesday, the 10-year yield was back up to 1.66 percent.

The reason the 10-year yield matters is because its movement tends to mimic the path of mortgage rates. When yields rise, rates often move higher.

Bankrate.com, which puts out a weekly mortgage rate trend index, found half the experts it surveyed predict rates will rise in the coming week.

“The coronavirus scare that spooked markets over the last week appears to be waning,” said Michael Becker, a branch manager at Sierra Pacific Mortgage in Lutherville, Md. “Stories reported in the press suggest the worst may be behind us. Whether this is true or not, I do not know, but markets have taken it as a good sign, so we will likely see higher Treasury yields and mortgage rates in the coming week.”

Meanwhile, borrowers taking advantage of lower rates propelled mortgage applications higher. According to the latest data from the Mortgage Bankers Association, the market composite index — a measure of total loan application volume — increased 5 percent last week. The refinance index jumped 15 percent, while the purchase index went down 10 percent.

The refinance share of mortgage activity accounted for 64.5 percent of applications.

“The continued decline in mortgage rates [led] to a 15 percent jump in refinances — the strongest level of activity since June 2013,” said Bob Broeksmit, MBA president and CEO. “This year’s drop in rates is pushing up home buyer demand, but supply in many areas is struggling to keep pace. Purchase applications took a step back as a result, but still remained 11 percent higher than a year ago.”

The MBA also released its mortgage credit availability index (MCAI) this week that showed credit availability decreased in January. The MCAI slipped 0.2 percent to 181.9 last month. A decline in the MCAI indicates lending standards are tightening, while an increase signals they are loosening.

“Mortgage credit availability was mostly unchanged to start 2020,” Joel Kan, an MBA economist, said in a statement. “Similar to December of 2019, the decline came from the reduction of low credit score, high-[loan-to-value] programs. Furthermore, there continues to be movement with both adds and drops in the government program space, with the net result last month showing small growth in the government index.”