Risk premium: Mortgages carry more risk than Treasury bonds, so lenders charge extra.
Loan duration: A 30-year mortgage keeps lenders exposed far longer than a 10-year Treasury.
Market conditions: Competition, investor demand, and overall sentiment all affect the spread.
Historically, the spread averages around 1.8%, widening during uncertainty and narrowing as confidence returns. Lately, it has been tightening—a positive sign for borrowers.