Rates on the 30-year fixed mortgages rose slightly this week, following increases in Treasury yields. Freddie Mac says the average rate rose to 4.74 percent this week from 4.71 percent the previous week. It hit a 40-year low of 4.17 percent in November.

The average rate on the 15-year loan slipped to 4.05 percent from 4.08 percent. It reached 3.57 percent in November, the lowest level on records starting in 1991.

Rates have changed little in the new year after spiking more than half a percentage point in the last two months. Investors sold off Treasurys bonds during that stretch, driving yields lower. Mortgage rates tend to track the yield on the 10-year Treasury note.