Ex-Coupon Bonds: What They Are, How They Work, and Real-World Examples

Table of Contents#

1. What Is an Ex-Coupon Bond?
2. Ex-Coupon vs. Cum-Coupon: Key Differences
3. How Ex-Coupon Pricing Works (Step-by-Step Example)
4. Why Do Ex-Coupon Bonds Exist?
5. Ex-Coupon for Preferred Stocks: A Quick Detour
6. Real-World Example: Corporate Bond Ex-Coupon Sale
7. Common Misconceptions About Ex-Coupon Securities
8. Final Thoughts: Is an Ex-Coupon Bond Right for You?
9. References

1. What Is an Ex-Coupon Bond?#

An ex-coupon bond (or “ex-interest bond”) is a fixed-income security sold without the right to the next scheduled coupon payment. When you buy an ex-coupon bond:

• The seller retains the next coupon (they get paid when it’s due).
• The buyer gets a discounted price to compensate for missing that coupon.

Ex-coupon applies to both bonds (interest payments = coupons) and preferred stocks (dividend payments = “coupons” for this purpose). The core idea is the same: the buyer sacrifices the next payment in exchange for a lower upfront cost.

Key Definitions to Know#

Before we go further, let’s clarify two critical terms:

• Coupon Payment: The fixed interest paid to bondholders (e.g., 5% annual coupon on a $1,000 par bond =$50/year).
• Accrued Interest: The interest that has built up since the last coupon payment. For ex-coupon bonds, this is the amount deducted from the cum-coupon price to get the ex-coupon price.

2. Ex-Coupon vs. Cum-Coupon: Key Differences#

The opposite of an ex-coupon bond is a cum-coupon bond (“with coupon”), where the buyer does receive the next coupon payment. The table below highlights the critical distinctions:

Example: Ex-Coupon vs. Cum-Coupon in Action#

Suppose you’re looking at a **$1,000 par bond** with a **5$25 every 6 months). The next coupon is due in 30 days.

• Cum-Coupon Price: $1,020 (includes$4.17 in accrued interest: $25 * (30/180)).
• Ex-Coupon Price: $1,020 -$4.17 = $1,015.83.

If you buy cum-coupon, you pay $1,020 and get the$25 coupon in 30 days. If you buy ex-coupon, you pay $1,015.83 but don’t get the next coupon (the seller does).

3. How Ex-Coupon Pricing Works (Step-by-Step Example)#

Ex-coupon pricing boils down to one formula:

$$\text{Ex-Coupon Price} = \text{Cum-Coupon Price} - \text{Accrued Interest}$$

To calculate this, you need three pieces of information:

1. The cum-coupon price (market price of the bond with coupon entitlement).
2. The accrued interest (interest earned since the last coupon).
3. The day count convention (how days are counted for interest calculations).

Step 1: Understand Day Count Conventions#

Bonds use different rules to calculate accrued interest. The two most common are:

• 30/360: Assumes each month has 30 days and a year has 360 days (used for corporate bonds).
• Actual/Actual: Uses the actual number of days in the period and year (used for U.S. Treasuries).

We’ll use the 30/360 convention for our example (simpler for beginners).

Step 2: Calculate Accrued Interest#

Accrued interest is calculated as:

$$\text{Accrued Interest} = \text{Coupon Payment} \times \left( \frac{\text{Days Since Last Coupon}}{\text{Days in Coupon Period}} \right)$$

Example: Accrued Interest Calculation#

Let’s use a corporate bond with the following details:

• Par Value: $1,000
• Coupon Rate: 6% annual (semiannual = 3% per period)
• Last Coupon Date: January 1
• Next Coupon Date: July 1 (180 days later)
• Current Date: May 1 (120 days since last coupon)

First, calculate the semiannual coupon payment:

$$\text{Coupon Payment} = 1,000 \times 0.03 = \$30$$

Next, calculate accrued interest (30/360 convention):

$$\text{Accrued Interest} = 30 \times \left( \frac{120}{180} \right) = \$20$$

Step 3: Find the Ex-Coupon Price#

Suppose the cum-coupon price (market price with coupon entitlement) is $1,040. The ex-coupon price is:

$$\text{Ex-Coupon Price} = 1,040 - 20 = \$1,020$$

Why This Matters: The buyer pays $1,020 instead of$1,040, but they don’t get the $30 coupon on July 1 (the seller does). The$20 discount compensates them for missing that payment.

4. Why Do Ex-Coupon Bonds Exist?#

Ex-coupon bonds aren’t a “trick”—they serve practical purposes for both buyers and sellers:

A. Sellers Want to Retain the Next Coupon#

If a seller holds a bond until just before the coupon date, they may want to keep the upcoming payment. For example:

• A retiree needs the $50 coupon for monthly expenses.
• A corporation wants to book coupon income for its quarterly financial statements.

Selling ex-coupon lets them keep the coupon while liquidating the bond.

B. Buyers Want a Discount (or Tax Benefits)#

Buyers might prefer ex-coupon bonds for:

• Lower Upfront Cost: A discounted price makes bonds more accessible for small investors.
• Tax Efficiency: Coupon income is taxed as ordinary income (up to 37% in the U.S.). Buying ex-coupon lets you delay taxable income until the next coupon period.

C. Market Liquidity#

Ex-coupon transactions help keep the bond market liquid. For example, if a large institutional investor wants to sell 10,000 bonds quickly, they might offer them ex-coupon to attract buyers seeking a discount.

5. Ex-Coupon for Preferred Stocks: A Quick Detour#

Ex-coupon rules apply to preferred stocks too—except we’re talking about dividends instead of coupons.

Example: Ex-Coupon Preferred Stock#

Suppose you’re looking at a **$50 par preferred stock** with a **4$0.50 every 3 months). The next dividend is due in 10 days.

• Cum-Dividend Price: $52.00 (includes$0.17 in accrued dividends: $0.50 * (10/30)).
• Ex-Dividend Price: $52.00 -$0.17 = $51.83.

If you buy ex-dividend, you pay $51.83 but don’t get the next$0.50 dividend (the seller does). The logic is identical to bonds—only the terminology changes.

6. Real-World Example: Corporate Bond Ex-Coupon Sale#

Let’s use a real corporate bond to bring this to life. We’ll pick the Apple Inc. 2.45% 2028 Bond (CUSIP: 037833BX4), which has:

• Par Value: $1,000
• Coupon: 2.45% annual (semiannual = $12.25 every 6 months)
• Next Coupon Date: July 1, 2024
• Ex-Coupon Date: June 15, 2024

Step 1: Calculate Accrued Interest#

As of June 15 (the ex-coupon date), 165 days have passed since the last coupon (January 1, 2024). Using the 30/360 convention:

$$\text{Accrued Interest} = 12.25 \times \left( \frac{165}{180} \right) = \$11.23$$

Step 2: Find Cum-Coupon vs. Ex-Coupon Price#

Suppose the cum-coupon price (before June 15) is $1,030.00. The ex-coupon price (after June 15) is:

$$1,030.00 - 11.23 = \$1,018.77$$

What Happens Next?#

• If you buy the bond on June 14 (cum-coupon), you pay $1,030.00 and get the$12.25 coupon on July 1.
• If you buy it on June 16 (ex-coupon), you pay $1,018.77 but don’t get the July 1 coupon (the seller does).

Total Return Comparison#

Let’s say you hold the bond for 6 months (until January 1, 2025). Here’s how the numbers stack up:

The cum-coupon buyer gets a higher total return—but they paid more upfront. The ex-coupon buyer saves money but sacrifices a coupon.

7. Common Misconceptions About Ex-Coupon Securities#

Let’s debunk three myths that trip up new investors:

Myth 1: “Ex-Coupon Means No Coupons Ever”#

False! Ex-coupon only applies to the next scheduled coupon. You’ll still get all subsequent coupons if you hold the bond. For example:

• Buy an ex-coupon bond in June (miss July coupon).
• Get the January, July, etc., coupons in future years.

Myth 2: “Ex-Coupon Bonds Are Always Cheaper (So They’re Better)”#

Not necessarily. You need to calculate the total return (price + coupons) over your holding period. For example:

• A cum-coupon bond costs $1,020 and gives$25 in coupons next month.
• An ex-coupon bond costs $1,000 but gives$0 next month.

The cum-coupon bond has a 2.45% one-month yield ($25/$1,020), while the ex-coupon bond has 0% yield for that month. The discount isn’t always worth it.

Myth 3: “Ex-Coupon Bonds Are Riskier”#

False! Risk is determined by credit quality (will the issuer pay back the bond?) and maturity (how long until you get your principal back)—not ex-coupon status. An ex-coupon bond from Apple is just as safe as a cum-coupon bond from Apple.

8. Final Thoughts: Is an Ex-Coupon Bond Right for You?#

To decide if an ex-coupon bond is a good fit, ask yourself these four questions:

1. Do You Need the Next Coupon for Cash Flow?#

If you rely on bond income to pay bills (e.g., retirees), buy cum-coupon. Ex-coupon bonds delay your next payment—bad for cash flow.

2. Are You Trying to Reduce Taxable Income?#

If you’re in a high tax bracket (32%+), ex-coupon bonds let you delay taxable coupon income. For example:

• Buying ex-coupon in December lets you avoid paying taxes on the January coupon until the next year.

3. Can You Afford to Wait for the Next Coupon?#

If you’re a long-term investor (holding 5+ years), the next coupon is a small part of your total return. Ex-coupon’s discount might help you build wealth faster.

4. Do You Understand the Accrued Interest Calculation?#

Always confirm the day count convention (30/360 vs. actual/actual) for the bond. A mistake here could mean you overpay for an ex-coupon bond.

9. References#

To learn more about ex-coupon bonds and fixed-income investing, check out these credible sources:

1. Investopedia: Ex-Coupon Definition
2. SEC: Investor Bulletin: Corporate Bonds
3. Fabozzi, F.J.: Fixed Income Securities: Tools for Today’s Markets (3rd Edition)
4. Fidelity: Understanding Bond Pricing

Wrapping Up#

Ex-coupon bonds are a powerful tool for fixed-income investors—but only if you understand how they work. The key takeaway? Ex-coupon isn’t good or bad—it’s a tradeoff: lower upfront cost in exchange for missing the next coupon.

By using the examples and checklists in this guide, you’ll be able to make informed decisions about ex-coupon securities—and avoid the mistakes that trip up even experienced investors.

Happy investing!