How Fixed Rate Bonds Work

Executive Summary

While the concept of a fixed rate bond is straightforward in principle — lend money, receive interest, get your principal back — the practical mechanics involve a few more moving parts that are worth understanding in detail. This article walks through the lifecycle of a fixed rate bond from issuance to maturity, using a simple, clearly labelled hypothetical example to illustrate how coupon payments are calculated and how a bond's cash flows unfold over time.

The Lifecycle of a Bond

A bond's life generally begins with issuance, at which point the issuer sets the face value, coupon rate, coupon frequency and maturity date. From issuance, the bond may be held by the original purchaser through to maturity, or it may change hands multiple times on the secondary market. Regardless of who holds it at any given time, the issuer's contractual obligation to pay coupons and repay principal at maturity generally remains unchanged — what does change is the price at which the bond trades between investors, which reflects prevailing market yields and the issuer's perceived creditworthiness at that point in time.

Consider a hypothetical illustrative bond issued with a face value of $1,000, an annual coupon rate of 4.5%, paid semi-annually, and a maturity of 7 years. Under this illustrative structure, the bond would pay $22.50 every six months ($1,000 × 4.5% ÷ 2), for a total of $45 per year, continuing for the seven-year term, at which point the final coupon payment of $22.50 and the $1,000 face value would generally both be paid, assuming the issuer meets its obligations in full.

Issue Price, Par, Premium and Discount

Bonds are not always bought or sold at exactly their face value. When a bond trades at its face value, it is described as trading 'at par'. When it trades above face value, it is trading 'at a premium', and when below, 'at a discount'. These movements generally reflect the relationship between the bond's fixed coupon rate and prevailing market interest rates for comparable bonds. For a purely illustrative example, if our hypothetical 4.5% coupon bond were later purchased on the secondary market for $980 rather than $1,000 — perhaps because market yields for similar bonds had risen since issuance — the buyer would be paying a discount to face value, which would generally increase their effective yield relative to the stated coupon rate, since they would still be entitled to the same $45 annual coupon and the full $1,000 at maturity.

• At par: purchase price equals face value; yield to maturity approximately equals the coupon rate.
• At a premium: purchase price exceeds face value; yield to maturity is generally lower than the coupon rate.
• At a discount: purchase price is below face value; yield to maturity is generally higher than the coupon rate.
• Accrued interest: a buyer purchasing between coupon dates generally compensates the seller for interest accrued since the last payment.

Accrued Interest and Secondary Market Trading

When a bond is bought or sold between scheduled coupon dates, the buyer generally compensates the seller for the portion of interest that has accrued since the last coupon payment, since the buyer will subsequently receive the full upcoming coupon regardless of how many days they have actually held the bond. This is generally reflected in the 'dirty price' (which includes accrued interest) versus the 'clean price' (which excludes it) quoted in secondary markets. Understanding this distinction can help investors interpret bond pricing quotes more accurately, particularly when comparing bonds purchased at different points in their coupon cycle.

A bond's coupon is fixed by contract, but the price you pay for that coupon stream — and therefore your effective yield — is set by the market.

Key Considerations for Investors

• Distinguish between a bond's coupon rate and its yield to maturity, which can differ materially depending on purchase price.
• Factor in accrued interest when comparing quoted prices for bonds purchased on the secondary market.
• Consider your own reinvestment plans for coupon income received prior to maturity.
• Check whether a bond has any call features that could result in early redemption ahead of the stated maturity date.
• Remember that all bond repayments remain subject to the issuer's ongoing capacity to meet its obligations.

Conclusion

Understanding the mechanics of coupon calculation, pricing conventions and the bond lifecycle provides a practical foundation for engaging with fixed rate bonds as an asset class. As illustrated in the hypothetical examples above, the interplay between coupon rate, purchase price and time to maturity determines the effective return an investor may achieve. This article is general information only and does not constitute personal financial advice; investors should seek professional guidance appropriate to their own circumstances.

Related topics

Information contained within these insights is provided for general information purposes only and does not constitute personal financial advice, an offer or recommendation to acquire or dispose of any financial product. Investors should consider their individual circumstances and obtain appropriate professional advice before making investment decisions.