With the ten year yield close to 1.50%, and based on an historical relationship, 30-year rates should currently be around 3.4%.
Mortgage News Daily reports that the most prevalent 30 year fixed rate is now at 3.13% for top tier scenarios. So mortgage rates are a little lower than expected.
The graph shows the relationship between the monthly 10 year Treasury Yield and 30 year mortgage rates from the Freddie Mac survey.
Currently the 10 year Treasury yield is at 1.48%, and 30 year mortgage rates were at 2.88% according to the Freddie Mac survey last week (should increase in the report this week).
The record low in the Freddie Mac survey was 2.65% in the week ending January 7, 2021 (Survey started in 1971).
Freddie Mac has a similar graph here with a linear fit (using data since 1990). Using their formula, 30 year rates would also be around 3.34%.
If the ten year yield rises to 2.0%, 30 year mortgage rates will probably increase to around 3.8% (still historically very low). This increase in rates will slow refinance activity, but probably have little impact on purchase activity.
Finally, here is a graph from Mortgage News Daily (MND) showing 30 year fixed rates from three sources (MND, MBA, Freddie Mac) since 1971. Mortgage rates are just above the all time record low.
If you go to MND and you can adjust the graph for different time periods.