Explanation

Mortgage pass-through security is most likely subject to the highest prepayment risk among the given options.

Analysis of each option:

1. Covered bond (Option A):

   • Covered bonds are debt securities backed by a pool of loans (typically mortgages) that remain on the issuer's balance sheet.
   • They have dual recourse: to the issuer and to the collateral pool.
   • Prepayment risk exists but is typically lower than mortgage pass-through securities because the issuer can manage the collateral pool and may have substitution rights.

2. Mortgage pass-through security (Option B):

   • These are securities where mortgage payments (principal and interest) are passed through to investors.
   • They have the highest prepayment risk because homeowners can refinance their mortgages when interest rates fall, leading to early principal repayment.
   • This creates uncertainty about cash flow timing and duration for investors.

3. Credit card receivable asset-backed security (Option C):

   • These are backed by credit card receivables.
   • They typically have very low prepayment risk because credit card balances are revolving and don't have fixed repayment schedules like mortgages.
   • Early repayments are less sensitive to interest rate changes compared to mortgages.

Key Concept:

Prepayment risk refers to the uncertainty about when borrowers will repay their loans early, which affects the timing and amount of cash flows to investors. Mortgage-backed securities are particularly vulnerable to prepayment risk because homeowners often refinance when interest rates decline.

Why Option B is correct:

• Mortgage pass-through securities directly expose investors to homeowner prepayment decisions
• No credit enhancement or structural features to mitigate prepayment risk
• Highly sensitive to interest rate changes
• Unlike covered bonds, there's no issuer guarantee or collateral substitution to manage prepayment risk