What Is Prepayment Risk?

What Is Prepayment Risk?

Let me explain prepayment risk to you directly: it's the risk you face as a fixed-income securities investor when your principal gets returned prematurely, cutting off those future interest payments you were counting on. This hits hardest with callable bonds and mortgage-backed securities. When debtors pay back part of the principal early, they stop making interest payments on that portion, so you as the investor miss out on that income. Bonds exposed to this risk often come with prepayment penalties to discourage early payoffs.

Understanding Prepayment Risk

You should know that prepayment risk shows up in certain callable fixed-income securities that the issuer can pay off early, or in mortgage-backed securities where the borrower does the same. These give the issuer or borrower the right—but not the obligation—to redeem before the scheduled maturity.

With a callable bond, the issuer can return your principal early, and after that, you get no more interest payments. Noncallable bonds don't have this feature, so prepayment risk only applies to callable ones—it's the chance the issuer pays back early, leaving you without those ongoing interest payments.

For mortgage-backed securities, homeowners might refinance or pay off their mortgages, meaning you as the security holder lose out on future interest. The cash flows here are uncertain, so you can't know the exact yield-to-maturity at purchase time. If you bought the bond at a premium (over 100), your actual yield ends up lower than what you estimated.

Criticism of Prepayment Risk

The main issue with prepayment risk is how it tilts everything in favor of the issuer, making interest rate risk one-sided against you as the investor. Callable bonds let issuers lock in low rates when rates rise, while you're stuck with lower returns when higher ones are out there. That creates an opportunity cost in a rising rate environment, and from a total return view, you also take a capital loss when rates go up.

When rates fall, you only benefit if the bonds aren't called—you keep getting the higher old rate and could sell for a gain. But issuers will call and refinance if rates drop a lot, so you can't capitalize on the change. Essentially, with callable bonds, you lose when rates rise but can't win when they fall.

In practice, corporate bonds often have call provisions, while government bonds rarely do. That's why government bonds can be a smarter choice in a falling rate environment, though corporate bonds offer higher long-term returns. You need to weigh prepayment risk alongside default risk before picking corporate over government bonds.

Requirements for Prepayment Risk

Not every bond carries prepayment risk—if it can't be called, there's no such risk. Remember, a bond is just a debt where an entity borrows from you, pays regular interest during the maturity period, and returns your principal at the end. Bonds are either callable or noncallable, and only the callable ones expose you to this risk.

Examples of Prepayment Risk

Take a callable bond: the higher its interest rate compared to current rates, the greater your prepayment risk. For mortgage-backed securities, the chance of refinancing spikes as market rates drop below the old ones.

For instance, if a homeowner has a 7% mortgage and rates fall to 4% or 5%, they're highly motivated to refinance. If they do, you as an investor in that mortgage on the secondary market won't get the full interest term. To stay in the market, you'd have to accept lower rates or take on more default risk.

If you buy a callable bond with a high rate, you're taking on prepayment risk. Mortgage prepayments also correlate with rising home values, as borrowers might trade up or do cash-out refinances, both leading to early payoffs.