Freddie Mac released its weekly update on national mortgage rates on Thursday morning, and once again, short- and long-term rates are moving in divergent directions.

Among fixed-rate mortgages (FRMs), 15-year FRMs and 30-year FRMs tacked on four basis points each, rising to 3.39% and 4.37%, respectively.

Adjustable-rate mortgages (ARMs) headed the other way, with 5/1 ARMs ticking down three basis points to 3.05%, and 1-year ARMs slipping five basis points to reach 2.52%.

Commenting on the results, Freddie Mac vice president and chief economist Frank Nothaft pointed to new data showing that new home sales in January were up 9.6% year over year.

This increasing demand for housing could explain why fixed-rate mortgages, at least, became more expensive. Combined with a 13.4% rise in the cost of housing over the course of last year, the higher rates on fixed-rate mortgages will only make homebuying more expensive.