I watch the spread between the 10 year US Treasury and the 30 year mortgage.
The lowest I’ve seen it get (2006-7) was around 1.4%.
Today, the 30 yr is at 3.72% and the 10 yr bond is 2.02 for a spread of 1.7%. Not the lowest, fairly high but not the highest either.
Lenders expecting higher rates is probably the answer. The 10 year has made a significant move up in yield lately.
Mortgage lenders react to rates, they don’t set them. Bondholders set rates through the auctions. At least that’s how I see it.