Understanding Fixed Income Yield in Nigeria
The rate advertised at a Treasury bill auction is not the return you actually earn — your real return, called the true yield, is always higher, because it’s calculated on what you actually paid, not the bill’s face value. This single gap — discount rate vs. true yield — trips up more Nigerian fixed income investors than almost anything else, and it can make an investment look better or worse than it really is.
Once you understand the two or three ways yield gets quoted, the confusion disappears. This guide covers discount rate vs. true yield for Treasury bills, coupon rate vs. current yield for bonds, and how to calculate your real return after tax and inflation. If you’re completely new to fixed income, our complete beginner’s guide covers the broader landscape first.
Quick Answer: The Five Yield Concepts
| Concept | What It Tells You | Used For |
|---|---|---|
| Discount Rate | The percentage discount applied to a Treasury bill’s face value | Quoting T-bill auction results |
| True Yield (Effective Yield) | Your actual annualized return based on the money you invested | Comparing T-bill returns with other investments |
| Coupon Rate | The fixed interest rate a bond pays on its face value | Quoting bond interest payments |
| Current Yield | Annual coupon divided by the price you paid | Comparing bonds bought at a discount or premium |
| Yield to Maturity (YTM) | Total return including coupon payments and any capital gain/loss at maturity | Comparing bonds with different prices |
What Is Yield?
Yield is the return you earn on an investment, expressed as a percentage per year — but not all yields are calculated the same way, and the number quoted isn’t always the number that matters.
In Nigerian fixed income, how yield is quoted depends on the instrument. Treasury bills use a discount rate; bonds use a coupon rate. Both can be converted into a true yield — the only figure that reflects what you’re actually earning on the money you put in. The quoted yield is your nominal return; after adjusting for inflation, you get your real return, which tells you whether your purchasing power actually grew.
Discount Rate: How Treasury Bill Returns Are Quoted
When the CBN auctions Treasury bills, results are published as a discount rate — the percentage by which a bill’s face value is reduced to arrive at the price you actually pay.
Worked example: a 364-day T-bill with a ₦100,000 face value and a 20% discount rate (the auction stop rate):
- Discount: ₦100,000 × 20% = ₦20,000
- Upfront cost: ₦100,000 − ₦20,000 = ₦80,000
- Profit at maturity: ₦20,000
The discount rate tells you the size of the discount — not your actual return. You invested ₦80,000, not ₦100,000, so your return should be calculated against what you actually put in.
True Yield: What You Actually Earn
True yield (also called effective yield) converts the discount into an annualized percentage based on the money you actually invested, not the face value.
True Yield Formula: True Yield = (Profit ÷ Amount Invested) × 100
Using the example above: (₦20,000 ÷ ₦80,000) × 100 = 25% — a full 5 percentage points higher than the 20% discount rate. For a given discount rate, longer tenors generally widen this gap further.
| Face Value | Discount Rate | Upfront Cost | Profit | True Yield |
|---|---|---|---|---|
| ₦100,000 | 18% | ₦82,000 | ₦18,000 | ~22% |
| ₦500,000 | 20% | ₦400,000 | ₦100,000 | ~25% |
| ₦1,000,000 | 22% | ₦780,000 | ₦220,000 | ~28% |
Use our Treasury Bill Calculator to convert any discount rate into a true yield and estimate your after-tax return instantly. For the full buying process, see our Treasury Bills guide.
Coupon Rate vs. Current Yield for Bonds
Bonds pay regular interest based on a fixed coupon rate rather than a discount — but your actual current yield depends on the price you paid, not just the coupon.
Buying a ₦1,000,000 FGN bond at a 15% coupon gets you ₦150,000 in annual interest, split into two ₦75,000 semi-annual payments. The coupon rate itself never changes over the bond’s life.
Current Yield Formula: Current Yield = (Annual Coupon ÷ Purchase Price) × 100
- Bought at face value (₦1,000,000): current yield equals the coupon rate, 15%
- Bought at a discount (₦900,000): (₦150,000 ÷ ₦900,000) × 100 = 16.67%
- Bought at a premium (₦1,100,000): (₦150,000 ÷ ₦1,100,000) × 100 = 13.64%
The coupon rate is fixed; the price you pay determines your actual return. See our FGN Bonds guide for more on how bonds work generally.
Yield to Maturity: The Full Picture for Bonds
Current yield ignores one important factor — the gap between what you paid and the face value you’ll receive at maturity. Yield to maturity (YTM) accounts for both the coupon payments and that capital gain or loss.
Buy a bond below face value and you collect interest and receive more than you paid at maturity — pushing YTM above current yield. Buy at a premium and the opposite happens. YTM is the most complete measure of a bond’s total return, though it’s also the most complex to calculate by hand. To avoid solving this equation manually, you can test different scenarios using an online Bond Yield to Maturity Calculator.
After-Tax and Real Yield: What You Actually Keep
Even true yield doesn’t tell the full story — tax and inflation both reduce what you actually keep.
After-Tax Yield
Treasury bills, fixed deposits, corporate bonds, and commercial papers carry a 10% withholding tax; FGN bonds are tax-exempt. Earn ₦100,000 in T-bill profit and you receive ₦90,000 after tax — your after-tax yield is meaningfully lower than the quoted rate. Always compare after-tax yields when weighing taxable against tax-exempt instruments. See our tax on fixed income guide for the full breakdown.
Real Yield (After Inflation)
Even at zero tax, inflation erodes returns. Earn 22% on a T-bill while inflation runs at 28%, and your real yield is −6% — a nominal profit that’s actually a loss in purchasing power. Use our Inflation Rate Tracker to check current inflation before locking into long tenors.
| Measure | Used For | Good for Comparing Instruments? |
|---|---|---|
| Discount Rate | Treasury Bills | No |
| True Yield | Treasury Bills | Yes |
| Coupon Rate | Bonds | No |
| Current Yield | Bonds | Better |
| Yield to Maturity | Bonds | Best |
Common Mistakes When Comparing Yields
| Mistake | What to Do Instead |
|---|---|
| Comparing a discount rate directly with a coupon rate | Convert everything to true yield or YTM first |
| Ignoring tax differences | Compare after-tax yields, especially between FGN bonds and T-bills |
| Forgetting inflation | A high nominal return means little if your real return is negative |
| Using face value to calculate T-bill returns | Always use your actual investment amount — the discounted price |
| Treating current yield as total return | For bonds you plan to hold to maturity, consider YTM instead |
Frequently Asked Questions
Why is true yield higher than the discount rate?
Because the discount rate is calculated on the bill’s face value, while true yield is calculated on the smaller amount you actually invested. Pay ₦80,000 and receive ₦100,000, and your true yield (25%) exceeds the 20% discount rate that produced it.
What is the difference between discount rate and true yield?
The discount rate is the percentage discount applied to a Treasury bill’s face value. True yield is your actual annualized return based on the money invested — always higher than the discount rate.
How do I calculate true yield on a Treasury bill?
(Profit ÷ Upfront Cost) × 100. Pay ₦80,000, receive ₦100,000 at maturity: (₦20,000 ÷ ₦80,000) × 100 = 25%.
What is a good yield on fixed income in Nigeria?
It depends on the instrument and current market conditions — always compare after-tax and after-inflation returns rather than headline rates alone. See our Treasury Bills and FGN Bonds guides for current ranges.
Is the coupon rate the same as a bond’s yield?
No. The coupon rate is the fixed percentage of face value paid annually. Yield depends on the price you actually paid — buy at a discount and your yield exceeds the coupon rate; buy at a premium and it falls below.
How do I compare returns across different fixed income instruments?
Convert everything to a true annualized yield, then adjust for tax and inflation — that gives you a fair, level comparison.
What’s the difference between nominal and real return?
Nominal return is the quoted yield before inflation. Real return is nominal return minus inflation, and it tells you whether your purchasing power actually increased.
Key Takeaways
- The discount rate quoted at a Treasury bill auction isn’t your actual return — true yield, based on what you invested, is always higher
- For bonds, the coupon rate is fixed, but your current yield depends on the price you paid
- Yield to maturity gives the most complete picture of a bond’s total return
- After-tax yield and real (inflation-adjusted) yield show what you actually keep
- Converting every quote to a comparable, after-tax, after-inflation figure avoids costly misunderstandings
Your Next Step
Next time you see a Treasury bill auction result or a bond quote, convert it to a true yield before comparing it against anything else — our Treasury Bill Calculator does this instantly. For the broader picture on choosing between instruments once you understand the real numbers, see our best fixed income investments in Nigeria guide.
This content is for educational purposes only and does not constitute financial advice. All investments carry risk, including the possible loss of capital. Rates and yields change with market conditions. Please do your own research or consult a licensed financial advisor before making any investment decision.
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