Bonds get sorted along five axes, and once you know them the whole market becomes easier to read: who issued the bond, how it pays interest, what options are attached to it, what secures it and how its credit is rated, and how the interest is taxed. Each axis changes the bond’s risk, yield, and behavior in a portfolio, which is why bond types explained side by side matter more than any single yield number. A 30-year corporate zero-coupon bond and a 2-year Treasury note are both “bonds,” but treating them as the same thing is like comparing a savings account to a venture capital bet.
Who Issued the Bond
The issuer is the most important classification because it tells you who owes you money and how likely they are to pay it back. Issuers fall into three broad camps, and the credit gap between them drives almost everything else about pricing.
U.S. Treasury Securities
Treasuries are debt issued by the federal government, backed by its full faith and credit. They carry the lowest default risk of any bond in the global market because the government has the power to tax and, ultimately, to print the currency the debt is denominated in.
Treasury Bills mature in one year or less and pay no periodic interest. You buy them at a discount and receive the full face value at maturity, and the difference is your return.1TreasuryDirect. Treasury Bills In Depth Treasury Notes come in 2-, 3-, 5-, 7-, and 10-year maturities and pay interest every six months. Treasury Bonds are the longest option, issued in 20- and 30-year maturities, also paying semiannual interest.2TreasuryDirect. Understanding Pricing and Interest Rates
Beyond direct Treasury issuance, government-sponsored enterprises like Fannie Mae and Freddie Mac issue agency bonds to support the mortgage market.3Federal Housing Finance Agency. Treasury and Federal Reserve Purchase Programs for GSE and Mortgage-Related Securities Agency debt carries an implicit government guarantee rather than the explicit full-faith-and-credit backing Treasuries have, and it pays slightly higher yields to compensate.
Municipal Bonds
State and local governments issue municipal bonds to fund public infrastructure like schools, highways, and water systems. Their main appeal is tax treatment, covered further down. Credit risk on any specific muni depends on what backs the repayment promise.
General Obligation bonds are secured by the issuing government’s taxing power. If revenue falls short, the municipality can raise taxes to cover the debt. That broad backing makes GO bonds the safer of the two main types. Revenue bonds rely solely on income from the specific project they financed. A toll road revenue bond gets repaid from toll collections, and if traffic disappoints, bondholders bear the consequences. Revenue bonds from the same municipality almost always carry higher yields than its GO bonds because the repayment source is narrower.
Corporate Bonds
Corporations issue bonds to raise capital for expansion, refinancing, or general operations. Credit quality here varies enormously. A bond from a dominant, cash-rich technology company behaves nothing like a bond from a leveraged startup. Corporate bonds sit lower in the safety hierarchy than government debt because companies have no taxing authority and face real bankruptcy risk.
Within a single company’s capital structure, seniority matters. Senior debt gets paid first if the company liquidates. Subordinated debt stands behind senior creditors. That priority ranking is one of the biggest determinants of what a corporate bond actually yields.
How the Bond Pays Interest
The payment structure shapes your cash flow, your tax picture, and how the bond’s price reacts to rate shifts. This is where bonds start diverging in ways that matter for portfolio construction.
Fixed-Rate Bonds
The fixed-rate bond is the default. You receive the same coupon payment, typically every six months, from the day you buy until the bond matures. Predictability is the appeal. The trade-off is price sensitivity to interest rates. When market rates rise above your bond’s fixed coupon, your bond’s price drops because new buyers can get better yields elsewhere. When rates fall, your bond’s price climbs. This inverse relationship between price and yield is the central mechanism of bond investing.
Floating-Rate Bonds
Floaters address the price volatility problem by periodically resetting their coupon to track a benchmark rate. The Treasury issues Floating Rate Notes that pay interest quarterly, with the rate tied to the most recent 13-week T-Bill auction and reset weekly.4TreasuryDirect. TreasuryDirect – Floating Rate Notes Corporate floaters more commonly reference the Secured Overnight Financing Rate, which replaced LIBOR for most U.S. dollar-denominated debt.
Because the coupon adjusts to prevailing rates, the market price stays relatively stable near face value. That stability costs you the price gains fixed-rate bonds enjoy when rates fall. Floaters are a defensive position, useful when you expect rates to rise or stay volatile.
Zero-Coupon Bonds
Zeros make no interest payments during their life. You buy at a steep discount and collect the full face value at maturity. A zero with a $1,000 face value might cost $600 today, and the $400 difference is your total return over the term.
The catch is taxes. Even though you receive no cash until maturity, the IRS requires you to report a portion of that built-in gain each year as income. The tax code calls this original issue discount, and it accrues based on the bond’s yield calculated at issuance.5GovInfo. 26 USC 1272 – Current Inclusion in Income of Original Issue Discount You owe tax on money you haven’t received yet. Zeros work best inside tax-advantaged accounts like IRAs or 401(k)s, where the phantom income doesn’t trigger an annual bill. Tax-exempt bonds, savings bonds, and short-term instruments with maturities of one year or less are exempt from the OID accrual rules.6Internal Revenue Service. Publication 550 (2025), Investment Income and Expenses
Treasury Inflation-Protected Securities (TIPS)
TIPS are a special category of Treasury debt built to protect purchasing power against inflation. The coupon rate is fixed, but the principal adjusts up or down based on changes in the Consumer Price Index for All Urban Consumers. Because interest is calculated on the adjusted principal, your semiannual payments grow when inflation rises and shrink during deflation.7TreasuryDirect. Treasury Inflation-Protected Securities (TIPS)
TIPS are issued in 5-, 10-, and 30-year terms.8TreasuryDirect. Glossary of Terms At maturity, you receive the inflation-adjusted principal or the original face value, whichever is greater. That deflation floor means you can never get back less than you started with, even if prices fall over the bond’s life.7TreasuryDirect. Treasury Inflation-Protected Securities (TIPS) Like zero-coupon OID, the annual inflation adjustment to TIPS principal is taxable each year even though you don’t receive the cash until maturity, making TIPS another candidate for tax-sheltered accounts.
Bonds With Embedded Options
Some bonds come with built-in features that let either the issuer or the investor change the deal before maturity. The party holding the option gains flexibility at the other party’s expense, and that shows up in the yield.
Callable Bonds
A callable bond gives the issuer the right to repay the debt early, typically after a specified non-call protection period. Many municipal bonds, for instance, become callable ten years after issuance. When rates drop, issuers exercise the call to refinance more cheaply.
For you, a call is unwelcome news. You get your principal back ahead of schedule and have to reinvest it in a lower-rate environment. To compensate for this reinvestment risk, callable bonds pay higher coupons than otherwise identical non-callable bonds. Some issuers add a small call premium above face value.
A variation called a make-whole call requires the issuer to pay you the present value of all remaining coupon payments and principal, discounted at a rate tied to Treasury yields plus a small spread. Make-whole calls are more common in corporate debt and far more expensive to exercise, which makes them unlikely outside of acquisition scenarios. The practical effect is near-certain cash flow stability while technically preserving the issuer’s ability to retire the debt.
Puttable Bonds
A puttable bond flips the option to your side. You have the right to sell the bond back to the issuer at a predetermined price on specified dates before maturity. You would exercise a put if rates have risen (making your below-market coupon less attractive) or if the issuer’s credit has deteriorated. The put creates a floor on losses and a guaranteed exit. Because the option benefits you, puttable bonds offer lower yields than comparable bonds without one.
Convertible Bonds
Convertibles straddle debt and equity. They start as regular corporate bonds paying a fixed coupon and include an option to convert into a set number of the issuer’s common shares at a predetermined conversion price. If the stock rises above the conversion price, you can swap the bond for shares and capture the upside. If the stock goes nowhere, you keep collecting coupons and get your principal back at maturity.
That embedded equity option isn’t free. Convertibles pay lower coupons than comparable non-convertible bonds from the same issuer because the conversion feature has standalone value. For the issuer, convertibles are a way to borrow at reduced interest cost today in exchange for potential share dilution later.
Security and Credit Quality
Security and credit quality answer one question: how likely are you to get your money back if things go wrong? Security is about what assets back the bond. Credit quality is an independent opinion on the issuer’s ability to pay.
Secured vs. Unsecured
A secured bond gives you a direct claim on specific assets if the issuer defaults. Mortgage bonds are backed by real property. Collateral trust bonds are backed by financial assets like stocks or other bonds held in trust. If the issuer enters bankruptcy, the pledged assets get liquidated to pay secured bondholders first.
Unsecured bonds, usually called debentures, have no specific collateral. You’re relying entirely on the issuer’s general ability to generate cash. In a liquidation, debenture holders stand behind secured creditors in line. That weaker position means debentures need to offer higher yields to attract buyers.
Investment Grade vs. High Yield
Credit rating agencies like S&P Global Ratings, Moody’s, and Fitch assign letter grades to bond issuances based on the issuer’s financial strength and likelihood of default. The scale runs from AAA (the strongest) down to D (already in default), and the critical dividing line sits between BBB- (or Baa3 on Moody’s scale) and BB+ (Ba1).9S&P Global Ratings. Understanding Credit Ratings
Everything rated BBB-/Baa3 and above is investment grade. These issuers have stable cash flows, manageable debt, and strong competitive positions. Many institutional investors like pension funds and insurance companies are restricted by regulation or internal policy to holding only investment-grade debt, which creates built-in demand and keeps yields relatively modest.
Anything rated BB+/Ba1 or below falls into high-yield territory, often called junk bonds. Issuers here have weaker finances, higher leverage, or uncertain outlooks. The market compensates with substantially higher coupon rates. High-yield bonds can deliver equity-like returns in good years and real principal loss in downturns. Credit analysis matters most in this corner of the market, because the difference between a BB issuer that survives and a CCC issuer that defaults can be your entire investment.
Tax Treatment
Two bonds with identical yields can produce very different after-tax returns depending on how their interest is taxed. Getting the tax classification wrong is one of the most common mistakes individual bond investors make, especially when comparing munis and corporates.
Taxable Bonds
Most corporate bonds and all Treasuries generate interest that is fully taxable at the federal level. Treasury interest, however, is exempt from state and local income taxes under federal law, which gives Treasuries a meaningful advantage over corporates for investors in high-tax states.10Office of the Law Revision Counsel. 31 USC 3124 – Exemption From Taxation
Tax-Exempt Municipal Bonds
Interest on state and local government bonds is excluded from federal gross income under Internal Revenue Code Section 103, with limited exceptions for certain private activity bonds and arbitrage bonds.11Office of the Law Revision Counsel. 26 USC 103 – Interest on State and Local Bonds If you live in the same state that issued the bond, the interest is often exempt from state and local taxes as well, creating what’s sometimes called a triple tax exemption.
The trade-off is yield. Munis pay lower nominal coupons than taxable bonds of similar credit quality. To compare them fairly, calculate the taxable equivalent yield by dividing the muni’s yield by one minus your marginal tax rate. A 3% muni yield, for example, is equivalent to roughly 4.6% on a taxable bond for someone in the 35% federal bracket. Skipping this calculation leads investors in lower tax brackets to buy munis that leave them worse off than a taxable alternative.
What Happens if You Sell Before Maturity
Selling in the secondary market triggers capital gains rules regardless of the bond type. If you sell for more than your adjusted cost basis, the profit is taxed as a short- or long-term capital gain depending on your holding period. This applies even to munis, where the interest income is tax-free but the capital gain is not.6Internal Revenue Service. Publication 550 (2025), Investment Income and Expenses
Bonds purchased at a premium above face value present another wrinkle. You can amortize that premium over the bond’s remaining life, reducing your taxable interest income each year. For taxable bonds, this amortization offsets interest dollar for dollar. If you buy bonds in the secondary market at a discount, the gain at maturity may be taxed as ordinary income rather than capital gains if the discount exceeds a small threshold.6Internal Revenue Service. Publication 550 (2025), Investment Income and Expenses
Maturity and Duration
Maturity tells you when you get your money back. Duration tells you how much the bond’s price will swing while you wait. Confusing the two costs people real money in volatile rate environments.
Maturity Buckets
Bonds are loosely grouped into short-term (roughly one to five years), intermediate-term (five to ten years), and long-term (beyond ten years). The ranges aren’t standardized and definitions vary by source, but the underlying principle is consistent: the longer the maturity, the more exposed you are to rate changes. You’re locking in today’s coupon for a longer stretch, so any shift in market rates opens a bigger gap between what your bond pays and what new bonds offer. Long-term bonds compensate for added volatility with higher yields. Short-term bonds give you more price stability and quicker access to principal but pay less.
Duration as the Real Measure of Rate Sensitivity
Maturity is only part of the story. A 10-year zero-coupon bond and a 10-year bond paying a 6% coupon have the same maturity but behave very differently when rates move, because the high-coupon bond returns cash sooner through its semiannual payments. Duration captures this by measuring the weighted average time until you receive all of a bond’s cash flows, factoring in both coupon payments and the final principal repayment.12FINRA. Brush Up on Bonds – Interest Rate Changes and Duration
As a rough rule, for every one-percentage-point change in interest rates, a bond’s price moves in the opposite direction by approximately its duration number. A bond with a duration of 7 years would lose about 7% of its value if rates jumped one full point.12FINRA. Brush Up on Bonds – Interest Rate Changes and Duration Higher coupons pull duration down because you’re getting more of your money back sooner. Longer maturities push duration up. Zero-coupon bonds have the highest duration of any bond at a given maturity because all cash flow arrives at the end. When you’re evaluating how much rate risk you’re actually taking on, duration is the number to watch.