Mortgage rates have been on a roller coaster lately, albeit a low-riding one. A mixed picture of rates last week, though, was enough to put the brakes on a recent rise in refinance demand.

The average rate for 30-year fixed loans with conforming balances and a 20% down payment increased slightly to 3.11% from 3.09% after two weeks of declines, according to the Mortgage Bankers Association. The 15-year fixed rate loan, used by about 1 in 5 refinance borrowers, decreased to 2.46%, the lowest level since January.

“The 10-year Treasury yield dropped sharply last week, in part due to investors becoming more concerned about the spread of Covid variants and their impact on global economic growth,” said Joel Kan, an MBA economist.

As a result, applications to refinance a home loan fell a seasonally adjusted 3% last week and were 18% lower than year ago. Refinance demand has been lower on an annual basis for a while because interest rates hit more than a dozen record lows last year, resulting in soaring refinance demand.

Mortgage applications to purchase a home fell 6% last week and were 18% lower year over year. High home prices are sidelining some buyers, and while the number of new listings is finally rising, the supply of homes for sale is still historically low, especially so in the more affordable categories.

Mortgage rates fell more sharply to start this week, after a major stock market sell-off Monday. Concerns over the delta variant and news of Olympic athletes and Major League Baseball players testing positive sent investors rushing to the relative safety of the bond market.

Refinances could get a boost going forward, after mortgage giants Fannie Mae and Freddie Mac last Friday announced they were removing an adverse market fee charged to lenders for all refinances. The fee was put in place at the start of the pandemic and was passed on to borrowers, so its removal could now be a source of more savings.