(That is mortgage rates adjust IMMEDIATELY when the 10 year moves up but they are quite sticky when it moves down)

SD,, I see rates move instantly up and down, even INTRA-day with certain lenders, while others only change rates once a day.
I have the luxury of seeing the spreads to anticipate saving a borrower an eighth or more.

The best lenders change rates in step with the market up OR down, that’s how I saw 5.50% for 2 days between two diff lenders last week, that spiked in the days afterwards.

I’m not disagreeing with you, but am not sure what your experience has been when rates fall. I’m a phone call away from the lock desk.

If you are basing your theory on what a mortgage person in between has told you, I’ll let you read between the lines.