Freddie Mac released its weekly update on national mortgage rates on Thursday morning, showing an increase in the average price for fixed-rate mortgages and no change in adjustable-rate mortgages.

Both 30-year fixed-rate mortgages (FRMs) and 15-year FRMs got more expensive over the past seven days, rising six basis points apiece. 30-year FRMs now average 4.33% interest, and 15-year FRMs cost 3.39%. One year ago, 30-year FRMs cost 3.40%, and 15-years 2.61%.

Neither 5/1 adjustable-rate mortgages (ARMs) nor 1-year ARMs, however, changed in price at all. 5/1 ARMs cost 3.03%, just like a week ago, and 1-year ARMs are still 2.44%. A year ago, these rates were 2.58% and 2.62%, respectively.

The fact that existing-home sales declined 0.2% in March, while new-home sales fell 15% would ordinarily be expected to push mortgage interest rates down, rather than up. However, Freddie Mac vice president and chief economist Frank Nothaft  noted in a statement a possible connection between the unexpected rise in long-term fixed mortgage rates and an "uptick" in 10-year Treasury yields over the past week.

Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.

Compare Brokers