Callable Bond

A callable bond (also called a redeemable bond) is a bond that gives the issuer the right, but not the obligation, to repay the debt before its stated maturity at a pre-agreed call price. Issuers usually call bonds when interest rates have fallen, so they can refinance at a lower cost. Corporate issuers, US municipalities, banks and some governments issue callable debt.

The call right is an option held by the issuer and sold, in effect, by the investor. In return, investors demand a higher coupon or yield than on an otherwise identical non-callable bond. The feature is the mirror image of a puttable bond, where the investor holds the option. For accounting purposes the call is an embedded derivative, usually treated as closely related to the debt host when the call price is close to the bond's amortized cost.

Think of renting out a room to a lodger who can move out early whenever a cheaper room becomes available, while you cannot ask them to leave. If rents in town fall, the lodger leaves and you have to find someone new at a lower rent. If rents rise, the lodger stays put at the old rate. To make up for that one-sided deal, you charge a bit more rent from the start.

A callable bond works the same way, with the roles reversed. The borrower can pay you back early when borrowing gets cheaper, leaving you to reinvest your money at lower rates. If rates rise, they keep the loan. The higher interest you receive is your payment for accepting that.

The bond's terms set out when and at what price it can be called:

• Call protection. Most callable bonds cannot be called for an initial period, such as five years on a ten-year corporate bond. Many US municipal bonds are callable after about ten years.
• Call price and schedule. The call price is often set at par plus a premium that declines over time, for example 102 in the first callable year, then 101, then 100.
• Make-whole call. Common on investment-grade bonds, this lets the issuer redeem at any time for the present value of the remaining payments discounted at a government yield plus a small spread. Because it compensates investors fully, it is rarely used for refinancing.
• Other forms. Bonds may be callable continuously after the protection period, only on coupon dates (Bermudan style), or on one date (European style). Sinking fund provisions require partial calls on a schedule.

Callable structures are common in high-yield bonds, where issuers want flexibility to refinance after their credit rating improves. Bank capital instruments are also typically callable, subject to supervisory approval.

Because the bond may not run to maturity, investors calculate the yield assuming it is called at the first opportunity. The yield to call $y$ solves:

• $P$ is the bond's current price.
• $C$ is the coupon payment per period, set by the coupon rate.
• $CP$ is the call price.
• $n_c$ is the number of periods until the call date.

Worked example: a bond with a 6% annual coupon and ten years left trades at 104 (1,040 per 1,000 face). It can be called at par in two years. Its yield to maturity is about 5.47%, but solving the equation above with $n_c = 2$, $C = 60$ and $CP = 1{,}000$ gives a yield to call of about 3.88%. The lower of the yields across all call dates and maturity is the "yield to worst", here 3.88%, which is the figure a careful buyer would rely on when the bond trades at a premium.

A callable bond can be valued as an ordinary bond minus the value of the issuer's call option:

If a comparable non-callable bond is worth 1,050 and the call option is worth 35, the callable bond is worth 1,015. As rates fall, the call option becomes more valuable and the bond's price rises more slowly than a straight bond's, staying close to the call price. This "price compression", or negative convexity, means investors give up much of the upside from falling rates while keeping most of the downside from rising rates. Dealers usually price the option with interest rate tree or simulation models and quote an option-adjusted spread to compare callable bonds with straight ones. Callable bonds therefore behave somewhat like mortgage-backed securities, whose borrowers can also prepay when rates fall.

• Reinvestment risk. When a bond is called, the investor gets cash back just when rates are low and must reinvest at worse yields.
• Uncertain duration. The effective life of the bond changes with rates, making interest rate risk harder to measure and hedge.
• Limited price gains. The call price acts as a soft cap on what the bond is worth.

Against these, investors receive extra yield. Whether it is enough depends on the option's value, which rises with rate volatility. Retail investors in particular are often advised to compare yield to worst rather than the headline yield. Other features can be combined with a call; a convertible bond is often callable, letting the issuer force conversion when its share price is high.

• Financial Industry Regulatory Authority (FINRA)
• Municipal Securities Rulemaking Board