Explanation

Correct Answer: B - Sharp changes in housing prices

Why this is correct:

• Sharp changes in housing prices (particularly increases) can lead to increased prepayments as homeowners may choose to refinance their mortgages to take advantage of lower interest rates or extract equity from their homes.
• When housing prices rise significantly, homeowners gain more equity in their properties, making them eligible for better refinancing terms.

Why other options are incorrect:

A. Stagnation in housing prices: This typically leads to decreased prepayments as homeowners have less incentive to refinance when property values are stable or not appreciating.

C. Increasing interest rates: Higher interest rates discourage refinancing and actually lead to decreased prepayments, as homeowners are less likely to give up their existing lower-rate mortgages.

D. Approaching original distribution day: This is not a recognized factor that influences prepayment behavior in MBS. Prepayments are driven by economic factors like interest rates, housing prices, and borrower behavior, not by calendar dates related to security distribution.

Key Concepts:

• Prepayment Risk: The risk that homeowners will pay off their mortgages earlier than expected, affecting MBS cash flows.
• Refinancing Incentive: When interest rates fall or housing prices rise, homeowners have greater incentive to refinance, leading to increased prepayments.
• Burnout Effect: After periods of heavy refinancing, the remaining pool of mortgages may have less incentive to refinance, reducing prepayment rates.