Coupon Rate: Fixed vs Floating
Coupon Rate: Fixed vs Floating
A coupon rate is the percentage of face value paid to you each year. It is set at issue and stays the same for the bond's life (fixed coupon), or it resets periodically based on a benchmark rate (floating coupon).
Key takeaways
- A fixed coupon remains constant throughout the bond's life; a floating coupon adjusts periodically based on a reference rate plus a spread
- Fixed coupons expose you to interest rate risk: if market rates rise, your fixed payments become less attractive and the bond's market value falls
- Floating coupons reduce interest rate risk because the payments rise and fall with the market; the bond's price stays closer to par
- Most U.S. corporate and Treasury bonds are fixed coupon; floating coupons are more common in bank loans and institutional debt
- The coupon is always calculated as a percentage of par value, not your purchase price
Fixed coupons: the traditional bond
A fixed coupon bond is issued with a coupon rate that does not change. If you buy a 10-year corporate bond with a 4% coupon and $1,000 par, you will receive 4% of $1,000 every year (or half that semi-annually) until maturity. That is $40 per year, or $20 every six months. On the maturity date, you get the final coupon payment plus the $1,000 principal back.
The fixed coupon is simple and predictable. You know exactly what cash you will receive on every payment date. This is why most retail investors hold fixed coupon bonds. You can plan around the income. A retiree living on bond income wants certainty; floating rates introduce unpredictability.
The downside of fixed coupons emerges when interest rates rise after you buy. Suppose you own that 4% coupon bond but rates rise to 6%. New bonds being issued today pay 6%, so your 4% bond is less attractive. If you try to sell before maturity, the market will price your bond lower to compensate. Your 4% coupon is now below the going rate, so you take a capital loss if you sell. This is interest rate risk—the risk that rising rates will erode the market value of your fixed coupon bond.
Conversely, if rates fall to 2%, your 4% coupon is now above the market. Your bond becomes more valuable. If you sell, you can take a capital gain. But you do not have the option to lock in that gain within the bond's structure; you must sell to realize it.
Fixed coupons are standard for government bonds (Treasuries, gilts, bunds), corporate bonds, and municipal bonds in most Western markets. The investor base is broad, the secondary market is deep, and the simplicity of fixed payments is understood by all parties.
Floating coupons: adapting to rate changes
A floating coupon bond has a coupon that resets at fixed intervals—quarterly, semi-annually, or annually—to a benchmark rate plus a fixed spread. The most common benchmarks are:
- SOFR (Secured Overnight Financing Rate) — the modern U.S. overnight funding rate, replacing LIBOR
- LIBOR — the London Interbank Offered Rate (being phased out; LIBOR fixings ended in 2021)
- Prime rate — the U.S. bank prime lending rate
- Treasury rates — the yield on a specific Treasury security (e.g., 3-month T-bill or 2-year note)
- CPI — the Consumer Price Index, used for inflation-linked bonds
The coupon is set as Benchmark + Spread. For example, a floating bond might reset quarterly to SOFR + 150 basis points (1.5%). If SOFR is at 5.5%, your quarterly coupon is 7%. Three months later, if SOFR falls to 5.2%, your coupon drops to 6.7%.
Floating rate bonds reduce interest rate risk. When rates rise, your coupon rises too, so the bond stays attractive. When rates fall, your coupon falls, but you do not take a capital loss because the bond's price does not swing as wildly. Floating rate bonds trade close to par because their coupon is always roughly aligned with the market rate.
This comes at a cost: unpredictability. You do not know in advance how much cash you will receive in future coupon periods. A retiree or conservative investor may dislike this uncertainty. Also, if you sell a floating bond before maturity, you have some interest rate risk because the price will still move if the credit quality or spread changes, or if there is a mismatch between the reset date and the settlement date.
When is each used?
Fixed coupons dominate the investment-grade bond market. Treasuries are fixed. Corporate bonds issued by large firms are fixed. Municipal bonds are fixed. These are familiar to retail investors and institutions alike. The vast majority of bonds outstanding carry fixed coupons.
Floating coupons are more common in:
- Bank loans — syndicated loans to corporations often have floating coupons tied to LIBOR or SOFR
- Institutional debt — private placements and direct lending deals
- Structured products — floating coupons are embedded in many securitized products and mortgage-backed securities
- Emerging market debt — some EM borrowers issue floating coupon bonds to limit their currency and interest rate risk
- Preferred shares — some preferred equities have floating coupons tied to Treasury or swap rates
A floating rate bond fund (FRB or similar ticker) might own a mix of bank loans and floating rate corporate notes. These funds appeal to investors who fear rising rates and want to avoid the duration risk of fixed coupon bonds.
Stepped coupons and other variants
Some bonds have coupons that change according to a schedule, not a benchmark. A "stepped" coupon bond might pay 2% for the first two years, 3% for the next two years, and 4% thereafter. This is neither fixed (it changes) nor floating (it is not tied to a market rate). Stepped coupons are less common but appear in some corporate and government bonds, especially those with longer maturities.
The interaction between coupon and price
The coupon rate is always a percentage of par, never of your purchase price. Suppose you buy a $1,000 par bond with a 4% coupon for $900. You still receive $40 per year, not $36 (4% of $900). The coupon payment is fixed to the par amount.
However, your yield—the return you actually earn—depends on what you paid. If you paid $900 for a 4% coupon bond, your current yield is 4% ÷ $900 = 4.44%. Your yield to maturity (the IRR) will be higher still, because you will receive $1,000 at maturity, giving you the additional $100 profit over the bond's life.
This is crucial: the coupon rate is a feature of the bond itself; it does not change with price. The yield changes based on what you paid. Understanding this separation clarifies why bonds with the same coupon can have different yields.
Fixed vs floating in practice: historical context
In the 2010s, when interest rates were near zero and central banks signaled rates would stay low for years, floating rate bonds were unattractive. You got almost no income, and rates were unlikely to rise. Fixed coupon bonds, even at low coupon rates, offered more certainty.
By 2022–2023, as central banks raised rates rapidly, floating rate bonds became attractive again. SOFR and LIBOR rose sharply, so floating rate coupons increased. An investor owning a SOFR + 150 basis point note that was earning 2% in 2021 was earning 7% by 2023. Fixed coupon bond holders, meanwhile, faced capital losses as their low coupons became uncompetitive in a higher-rate environment.
Credit spread and floating coupons
The spread (for example, SOFR + 150 bps) reflects the creditworthiness of the issuer. A bank with strong credit might borrow at SOFR + 100 bps. A weaker bank might pay SOFR + 300 bps. The spread is set at issue and does not change (though the total coupon changes as the benchmark moves). This is how markets price credit risk on floating rate debt: a wider spread compensates for higher default risk.
Callable bonds and coupons
A callable bond allows the issuer to repay early at par, usually if rates fall enough to make refinancing attractive. The coupon, whether fixed or floating, does not change if the bond is called. You still receive the coupon and par, just sooner than the stated maturity. But the call option affects the yield you actually earn (yield to call may be lower than yield to maturity if the bond is likely to be called).
Converting between fixed and floating
Some bonds have conversion options, and some floating rate bonds have "collars"—a floor and ceiling on the coupon. A collar might specify that a SOFR + 200 bps coupon cannot fall below 1% or rise above 6%. This limits the interest rate risk while keeping some floating-rate upside. Collars are common in structured products and some institutional bonds.
Coupon reinvestment and your total return
Even if you hold a fixed coupon bond to maturity, you face reinvestment risk. The coupon payments you receive (e.g., $40 per year) must be reinvested. If rates fall between the coupon payment date and the date you reinvest, you will earn less on that cash. Your total return depends not just on the coupon and principal you receive, but on the rates available when you reinvest those interim payments.
Floating coupon bonds partly address this: as rates fall, your coupon falls, but the cash you receive from coupons is lower, so you are reinvesting less at the lower rate. This is a form of natural hedge, though it does not eliminate reinvestment risk.
Accrued interest on fixed vs floating coupons
Both fixed and floating coupon bonds accrue interest daily and you pay accrued interest when you buy them in the secondary market. A fixed coupon's accrual is straightforward: the coupon is known, so the daily accrual is coupon ÷ 365 (or 360, depending on market convention). A floating coupon's accrual is trickier: the next coupon is unknown until the reset date, so accrued interest is estimated using the previous coupon or a flat rate agreed in the trade.
Conclusion: coupon certainty vs rate alignment
Fixed coupons give you certainty about cash flows and are easier to understand, but they expose you to interest rate risk. Floating coupons protect against rising rates but introduce payment uncertainty. Neither is superior; they suit different goals. A fixed income investor building a stable income stream prefers fixed coupons and manages duration risk separately. A trader or an investor in a rising-rate environment prefers floating coupons to stay competitive with market rates. Most retail investors own fixed coupon bonds through funds or direct holdings, making fixed coupons the more familiar option.
Decision tree
Related concepts
Next
Now that you know what rate is paid and how it is set, the next step is understanding how long you will receive those payments—the maturity and tenor of the bond.