A zero‑coupon bond (also called an accrual bond) is a debt security that pays no periodic interest (no coupons). Instead it is sold at a deep discount to its face (par) value and repays the full par amount at maturity. The investor’s return equals the difference between the purchase price and the maturity value; that return accrues (is imputed) over the life of the bond.
Key features (summary)
– Issued at a deep discount; redeemed at par at maturity.
– No periodic interest payments; interest is “imputed” (phantom interest).
– Common issuers: U.S. Treasury (STRIPS), state and local governments (munis), and corporations.
– Typically long maturities (10+ years are common), although shorter issues exist.
– Price is very sensitive to changes in market interest rates (high duration).
– Imputed interest is generally taxable each year unless held in a tax‑advantaged account or the bond is tax‑exempt.
How zero‑coupon bonds work
– Issue: An issuer (gov’t or corporation) can issue a bond with no coupons, or existing coupon bonds can be “stripped” (coupons separated from principal) and sold as zero‑coupon instruments (e.g., Treasury STRIPS).
– Purchase: Investors buy the bond at a price well below par.
– Accrual: The bond’s value increases as it approaches maturity; the increase represents imputed interest.
– Redemption: At maturity the investor receives the face value (par).
Pricing a zero‑coupon bond
Price formula:
Price = M / (1 + r)^n
where:
– M = maturity (face) value
– r = required annual yield (decimal)
– n = years to maturity
Example (from source): If you want a 6% annual return on a bond that pays $25,000 at maturity in 3 years:
Price = 25,000 / (1 + 0.06)^3 = 25,000 / 1.191016 ≈ $20,991
You pay $20,991 now and receive $25,000 in 3 years. The $4,009 difference is the return (≈6% p.a.).
Another example: A bond with $20,000 face value maturing in 20 years with a 5.5% yield would sell for about $6,855 because 6,855 × (1.055)^20 ≈ $20,000.
Why price moves more than coupon bonds
Zero‑coupon bonds have all cash flow concentrated at maturity, so their duration is (roughly) equal to their maturity. That makes them more sensitive to interest‑rate changes than coupon bonds of the same maturity, which receive periodic cash flows that shorten effective duration.
Taxation and “phantom” (imputed) interest
– The accrued (imputed) interest on a zero‑coupon bond is generally taxable as income each year, even though no cash interest is paid until maturity. This is often called “phantom income.”
– The IRS treats original issue discount (OID) and uses rules to calculate and allocate the imputed interest over the life of the bond (see 26 USC §1274).
– Treasury-related rules: the IRS uses an accretive method and sets minimum rates for imputed interest on Treasuries (refer to IRS and SEC guidance).
– Ways to avoid current taxation on imputed interest:
• Hold zeros in a tax‑deferred account (IRA, 401(k)).
• Buy municipal zero‑coupon bonds that are tax‑exempt at the federal (and sometimes state/local) level.
• Buy in accounts or structures where the interest is exempt or deferred under tax law.
(See U.S. Securities and Exchange Commission and IRS Topic No. 403.)
How zero‑coupon bonds differ from regular (coupon) bonds
– Coupon bonds pay periodic interest and return principal at maturity.
– Zero‑coupon bonds pay no periodic interest and return only the face value at maturity; their return is embedded in the deep discount at purchase.
Advantages of zero‑coupon bonds
– Predictable lump‑sum at maturity — good for funding a fixed future liability (college, a future purchase).
– No reinvestment risk on coupons (no periodic coupons to reinvest at uncertain rates).
– Potentially higher capital appreciation if yields fall.
Risks and disadvantages
– Interest-rate risk: large price swings if market rates change.
– Credit/default risk (for corporate and some municipal zeros): issuer may default on the final payment.
– Liquidity risk: some zero markets are less liquid; selling before maturity may be costly.
– Tax consequences: taxable phantom interest can create cash‑flow/tax burdens unless held in a tax‑favored account or the issue is tax‑exempt.
– Possible call risk: some zero bonds may be callable (issuer redeems early), reducing expected return.
Practical steps to evaluate and buy zero‑coupon bonds
1. Define your goal and time horizon
• Use zeros for specific future needs (tuition, retirement milestone) that align with the bond’s maturity.
2. Choose issuer and tax status
• U.S. Treasury STRIPS: backed by the U.S. government, low credit risk, taxable at federal level.
• Municipal zero‑coupon bonds: often tax‑exempt at the federal level (and possibly state/local) — good if you want tax‑free income.
• Corporate zeros: higher yields but higher credit risk.
3. Decide account type
• If you want to avoid taxable phantom income, buy zeros inside tax‑deferred accounts (IRAs, 401(k)s).
• Otherwise consider tax‑exempt municipal zeros if you need a taxable account.
4. Calculate required yield and price
• Use Price = M / (1 + r)^n to see what price you should pay for your target yield.
• Alternatively, if you know the price, solve for r to find the bond’s yield to maturity.
5. Assess risks and features
• Check maturity, call provisions (if any), credit rating (for corporates/munis), and market liquidity.
• Consider interest‑rate scenario analysis: estimate price change for plausible rate movements.
6. Choose purchase method
• Treasury STRIPS: buy through TreasuryDirect or a broker.
• Corporate/municipal zeros: buy via a broker, through primary offerings, or on secondary markets.
• Consider laddering multiple maturities to reduce reinvestment and interest‑rate timing risks.
7. Plan for taxes and reporting
• If held in a taxable account, be prepared to report OID/imputed interest each year (consult a tax advisor).
• If tax‑exempt munis, confirm the exemption scope (federal and state) and any alternative minimum tax (AMT) implications.
8. Decide hold or sell strategy
• Most investors hold zeros to maturity to receive the lump‑sum and avoid price volatility.
• If selling before maturity, be aware of market prices and potential capital gains/losses.
Suitability and investor profile
– Good for investors with specific long-dated liabilities and the ability to tolerate price volatility before maturity.
– Not ideal for investors who need periodic income or who are highly sensitive to short‑term market value swings.
– Consider tax status—if you cannot or do not want to pay annual taxes on imputed interest, use tax‑favored accounts or tax‑exempt issues.
Bottom line
Zero‑coupon bonds offer a straightforward way to lock in a future lump‑sum payment by buying deeply discounted debt today. They are particularly useful for long-term, goal‑specific saving but come with higher interest‑rate sensitivity and the potential for annual “phantom” taxation on imputed interest. Selecting the right issuer, maturity, account type, and purchase price—and understanding tax treatment—are the key steps to using zeros effectively.
Sources and further reading
– Investopedia, “Zero‑Coupon Bond” (Laura Porter)
– U.S. Securities and Exchange Commission, “Zero Coupon Bond”
– U.S. Code, 26 USC §1274 (Original issue discount rules)
– Internal Revenue Service, Topic No. 403, Interest Received —
Editor’s note: The following topics are reserved for upcoming updates and will be expanded with detailed examples and datasets.