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What is a bond?

Key takeaways

  • A bond is a loan to a government, agency, or company that is repaid with interest.
  • Bonds complement stocks and other more aggressive investments in a portfolio.

The IOUs of the financial world, bonds represent a government's, agency's, or company's promise to repay what it borrows—plus interest. Though they typically don't make the attention-grabbing moves that stocks do, bonds still can play a vital part of your financial plan, providing a sense of stability and consistent income.

Most bonds pay regular interest until the bond matures.

What is a bond?

A bond is essentially a loan an investor makes to a borrower. As with loans that you take out yourself, bond investors expect to receive full repayment of what was borrowed and consistent interest payments.

Many investors value bonds for the regular income they offer through these interest payments, as well as the comparative safety they provide compared to stocks. While stock values fluctuate day to day, highly rated bonds essentially assure investors that they will see repayment of the amount they invested plus modest interest. Going back more than 90 years, investment-grade bonds as a category have not had a single 5- or 10-year period in which they offered negative returns.1

This makes them valuable for investors to help diversify and minimize the risk in their investment portfolios. For more on the role bonds can play in a portfolio, see our guide to diversification.

How do bonds work?

There are a few key terms to keep in mind when it comes to understanding how bonds work:

Issuer This is the government, government-sponsored enterprise, or company that seeks to fund its activities with a loan. It issues bonds as part of its promise to repay its debts.

Maturity date Generally, this is when you will receive repayment of what you loaned an issuer (assuming the bond doesn't have any call or redemption features). If you want or need to sell a bond before its maturity date, you may be able to sell it to someone else, though there is no guarantee you will get what you paid.

Face value (a.k.a. par value) This is the value the bond holder will receive at maturity unless the issuer fails to repay the loan, a practice called defaulting. Investors usually pay par when they buy a bond from the issuer, unless it's a zero-coupon bond, which we cover more below. If investors buy the bond from someone else (meaning they buy it on a secondary market), they may pay more or less than face value. Check out our guide on bond prices, rates, and yields for more on how bond rates change over time.

Coupon rate This is the annual percentage of interest the issuer pays someone who owns a bond. The term "coupon" originates from when bond certificates were issued on paper and had actual coupons that investors would detach and bring to the bank to collect the interest. Bonds may have fixed, unchangeable rates or floating coupon rates, meaning they adjust over time based on a predetermined formula. Most bonds make interest payments semiannually based on the principal (the amount they originally borrowed), although some bonds offer monthly and quarterly payments.

Bond rating Bond ratings indicate the financial health of the issuer and how likely they are to repay their debts. Ratings agencies such as Standard & Poor's, Moody's, and Fitch assign a rating that indicates their opinion of whether the bond is "investment grade" or not. Higher-rated bonds are considered safer and can be attractive even with lower interest rates, whereas lower-rated bonds pay higher interest rates to compensate investors for taking on more perceived risk. An issuer's bond or credit rating can change over time.

Callability Callable bonds are bonds that the issuer can repay, or call back, early. The issuer may recall bonds if interest rates fall low enough that the issuer can issue comparable new bonds at substantially lower rates and save money overall. The attraction of callable bonds for investors is that callable bonds typically offer higher rates than noncallable bonds. However, there is no guarantee that an investor would be able to find a similar rate on a new bond—or even one equal to the current market rate when they buy their callable bond—if their bond is recalled. Callable bonds often have guidelines governing how soon they can be recalled and if the issuer must pay a premium on the principal if they do.

Zero-coupon bonds Also known as "strips," these are bonds that do not make periodic interest payments. In other words, there's no coupon. Instead, you buy the bond at a discount on its face value and receive one payment of the full face value at maturity. For example, you might pay $16,000 now on a 10-year zero-coupon bond with a face value of $20,000. In a decade, when the bond is mature, you’ll receive a payment of $20,000. Perhaps the best-known example of a zero-coupon bond is a US savings bond. Note: Investors interested in bonds may also consider brokered certificates of deposit (CDs), which work similarly to bonds: Not only do they return their full par value at maturity but they are also FDIC-insured, meaning they guarantee the return of your principal up to the FDIC limits. For more on CDs, see What is a CD?

Treasury bonds

The US Treasury issues bonds to pay for government activities and to service the national debt. Treasuries are considered to be extremely low risk if held to maturity, since they are backed by "the full faith and credit" of the US government. Because of their safety, they tend to offer lower yields than other bonds. Income from Treasury bonds is exempt from state and local taxes.

Agency bonds

Government-sponsored enterprises (GSEs), like Fannie Mae, Freddie Mac, and the Tennessee Valley Authority, issue bonds to support their mandates. That typically involves ensuring certain segments of the population—like farmers, students, and homeowners—can borrow at affordable rates.

Yields are higher than government bonds, representing their higher level of risk, though are still considered to be on the lower end of the risk spectrum. Some agency bonds, like Fannie Mae and Freddie Mac, are taxable. Others are exempt from state and local taxes.

Municipal bonds

Municipal bodies, which include states, cities, counties, and towns, issue bonds to pay for public projects (think: roads, sewers) and to finance other activities. The majority of these bonds, commonly called munis, are exempt from federal income taxes and, in most cases, also exempt from state and local taxes if the investor is a resident of the state that issues them. As a result, the yields tend to be lower but still may provide more after-tax income for investors in higher tax brackets.

Corporate bonds

Companies issue bonds to expand, modernize, cover expenses, and finance other activities. The yield is generally higher than government and municipal bonds, though they do carry more risk. Bond rating agencies help you assess that risk by grading the bonds based on the issuing company's creditworthiness, or how likely it is to repay its loans. Income from corporate bonds is fully taxable.

Mortgage-backed securities (MBS)

Banks and other lending institutions pool mortgages and "securitize" them so investors can buy bonds that are backed by income from people repaying their mortgages. This raises money so the lenders can offer more mortgages. Examples of MBS issuers include Ginnie Mae, Fannie Mae, and Freddie Mac. Mortgage-backed bonds have a yield that typically exceeds high-grade corporate bonds.

The major risk of these bonds is that if borrowers repay their mortgages in a "refinancing boom," it could have an impact on the investment's average life and potentially its yield. These bonds can also prove risky if many people default on their mortgages. Mortgage-backed bonds are fully taxable.

High-yield bonds

Some issuers simply aren't as creditworthy as others and must offer what are known as high-yield bonds. High-yield issuers can be local and foreign governments, but they're most commonly companies that are considered by bond ratings agencies to be at greater risk of not paying interest and/or returning principal at maturity. As a result, the issuer will pay a higher rate to entice investors to take on the added risk. These bonds are frequently rated below investment grade by credit agencies and are considered speculative; you may also hear them referred to as "junk bonds."

How to buy bonds

Most investors get exposure to different types of bonds through bond funds. These may be through mutual funds or exchange-traded funds (ETFs). In either case, they are researched and curated by professionals or aim to recreate the performance of indexes tracking leading bonds. Bond funds allow you to minimize your risk by investing in potentially hundreds of bonds at once and can readily be bought through regular investment accounts, like taxable brokerage accounts, individual retirement accounts (IRAs), and 401(k)s. In addition, you can easily sell shares regardless of bond maturity dates.

Some investors may choose to research and invest in new-issue and secondary market individual bonds through their brokerages. Investing in bonds this way allows investors to hold bonds to their maturity dates and avoid losses caused by price volatility. Doing so, however, requires a greater knowledge of the bond industry, credit ratings, and risk, and single bonds may be more difficult to sell quickly before their maturity date.

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1. Based on rolling monthly holding periods. Past performance is no guarantee of future results. Asset class total returns are represented by indexes from Fidelity Investments, Morningstar, Standard & Poor's and Bloomberg Barclays. Fidelity Investments proprietary analysis of historical asset class performance, which is not indicative of future performance. Source: Fidelity Investments (AART) as of 12/31/2019

In general, the bond market is volatile, and fixed income securities carry interest rate risk. (As interest rates rise, bond prices usually fall, and vice versa. This effect is usually more pronounced for longer-term securities.) Fixed income securities also carry inflation risk, liquidity risk, call risk, and credit and default risks for both issuers and counterparties. Unlike individual bonds, most bond funds do not have a maturity date, so holding them until maturity to avoid losses caused by price volatility is not possible. Any fixed income security sold or redeemed prior to maturity may be subject to loss.

Lower yields - Because of the inherent safety and short-term nature of a CD investment, yields on CDs tend to be lower than other higher risk investments.
Interest rate fluctuation - Like all fixed income securities, CD valuations and secondary market prices are susceptible to fluctuations in interest rates. If interest rates rise, the market price of outstanding CDs will generally decline, creating a potential loss should you decide to sell them in the secondary market. Since changes in interest rates will have the most impact on CDs with longer maturities, shorter-term CDs are generally less impacted by interest rate movements.
Credit risk - Since CDs are debt instruments, there is credit risk associated with their purchase, although the insurance offered by the FDIC may help mitigate this risk. Customers are responsible for evaluating both the CDs and the creditworthiness of the underlying issuing institution.
Insolvency of the issuer- In the event the Issuer approaches insolvency or becomes insolvent, it may be placed in regulatory conservatorship, with the FDIC typically appointed as the conservator. As with any deposits of a depository institution placed in conservatorship, the CDs of the issuer for which a conservator has been appointed may be paid off prior to maturity or transferred to another depository institution. If the CDs are transferred to another institution, the new institution may offer you a choice of retaining the CD at a lower interest rate or receiving payment.
Selling before maturity - CDs sold prior to maturity are subject to a mark-down and may be subject to a substantial gain or loss due to interest rate changes and other factors. In addition, the market value of a CD in the secondary market may be influenced by a number of factors including, but not necessarily limited to, interest rates, provisions such as call or step features, and the credit rating of the Issuer. The secondary market for CDs may be limited. Fidelity currently makes a market in the CDs we make available, but may not do so in the future.
Coverage limits- FDIC insurance only covers the principal amount of the CD and any accrued interest. In some cases, CDs may be purchased on the secondary market at a price that reflects a premium to their principal value. This premium is ineligible for FDIC insurance. More generally, FDIC insurance limits apply to aggregate amounts on deposit, per account, at each covered institution. Investors should consider the extent to which other accounts, deposits or accrued interest may exceed applicable FDIC limits. For more information on the FDIC and its insurance coverage visit

For the purposes of FDIC insurance coverage limits, all depository assets of the account holder at the institution issuing the CD will generally be counted toward the aggregate limit (usually $250,000) for each applicable category of account. FDIC insurance does not cover market losses. All the new-issue brokered CDs Fidelity offers are FDIC insured. In some cases, CDs may be purchased on the secondary market at a price that reflects a premium to their principal value. This premium is ineligible for FDIC insurance. For details on FDIC insurance limits, visit

Lower yields - Treasury securities typically pay less interest than other securities in exchange for lower default or credit risk.

Interest rate risk - Treasuries are susceptible to fluctuations in interest rates, with the degree of volatility increasing with the amount of time until maturity. As rates rise, prices will typically decline.

Call risk - Some Treasury securities carry call provisions that allow the bonds to be retired prior to stated maturity. This typically occurs when rates fall.

Inflation risk - With relatively low yields, income produced by Treasuries may be lower than the rate of inflation. This does not apply to TIPS, which are inflation protected.

Credit or default risk - Investors need to be aware that all bonds have the risk of default. Investors should monitor current events, as well as the ratio of national debt to gross domestic product, Treasury yields, credit ratings, and the weaknesses of the dollar for signs that default risk may be rising.

Some agency or GSE bonds have call features, which means they can be redeemed or paid off at the issuer’s discretion before maturity. Typically, an issuer will call a bond when interest rates fall, potentially leaving investors with a capital loss or loss in income and less favorable reinvestment options. For investors concerned about call risk, non-callable agency and GSE bonds are available in the marketplace. Like all bonds, GSE and agency bonds are susceptible to fluctuations in interest rates. If interest rates rise, bond prices will generally decline, despite the lack of change in both the coupon and maturity. The degree of price volatility due to changes in interest rates is usually more pronounced for longer-term securities. While agency and GSE bonds have relatively low credit risk, there is some risk that the issuing agency or GSE will default. Agency and GSE bonds are not an obligation of the U.S. government; credit and default risk is based on the individual issuer. While the yields on agency and GSE bonds are usually higher than those offered by Treasuries, there is a risk that the income generated may be lower than the rate of inflation. Inflation may diminish the purchasing power of a bond's interest and principal.

Interest income earned from tax-exempt municipal securities generally is exempt from federal income tax and may also be exempt from state and local income taxes if you are a resident in the state of issuance. A portion of the income you receive may be subject to federal and state income taxes, including the federal alternative minimum tax. You may also be subject to tax on amounts recognized in connection with the sale of municipal bonds, including capital gains and “market discount” taxed at ordinary income rates. Market discount arises when a bond is purchased on the secondary market for a price that is less than its stated redemption price by more than a statutory amount. Before making any investment, you should review the relevant offering's official statement for additional tax and other considerations.

The municipal market can be adversely affected by tax, legislative, or political changes, and by the financial condition of the issuers of municipal securities. Investing in municipal bonds for the purpose of generating tax-exempt income may not be appropriate for investors in all tax brackets or for all account types. Tax laws are subject to change, and the preferential tax treatment of municipal bond interest income may be revoked or phased out for investors at certain income levels. You should consult your tax advisor regarding your specific situation.

[When investing in corporate bonds, investors should remember that multiple risk factors can impact short- and long-term returns. Understanding these risks is an important first step towards managing them.]

Credit and default risk - Corporate bonds are subject to credit risk. It’s important to pay attention to changes in the credit quality of the issuer, as less creditworthy issuers may be more likely to default on interest payments or principal repayment. If a bond issuer fails to make either a coupon or principal payment when they are due, or fails to meet some other provision of the bond indenture, it is said to be in default. One way to manage this risk is diversify across different issuers and industry sectors.

Market risk - Price volatility of corporate bonds increases with the length of the maturity and decreases as the size of the coupon increases. Changes in credit rating can also affect prices. If one of the major rating services lowers its credit rating for a particular issue, the price of that security usually declines.

Event risk - A bond’s payments are dependent on the issuer’s ability to generate cash flow. Unforeseen events could impact their ability to meet those commitments.

Call risk - Many corporate bonds may have call provisions, which means they can be redeemed or paid off at the issuer’s discretion prior to maturity. Typically an issuer will call a bond when interest rates fall potentially leaving investors with a capital loss or loss in income and less favorable reinvestment options. Prior to purchasing a corporate bond, determine whether call provisions exist.

Make-whole calls - Some bonds give the issuer the right to call a bond, but stipulate that redemptions occur at par plus a premium. This feature is referred to as a make-whole call. The amount of the premium is determined by the yield of a comparable maturity Treasury security, plus additional basis points. Because the cost to the issuer can often be significant, make-whole calls are rarely invoked.

Sector risk - Corporate bond issuers fall into four main sectors: industrial, financial, utilities, and transportation. Bonds in these economic sectors can be affected by a range of factors, including corporate events, consumer demand, changes in the economic cycle, changes in regulation, interest rate and commodity volatility, changes in overseas economic conditions, and currency fluctuations. Understanding the degree to which each sector can be influenced by these factors is the first step toward building a diversified bond portfolio.

Interest rate risk - If interest rates rise, the price of existing bonds usually declines. That’s because new bonds are likely to be issued with higher yields as interest rates increase, making the old or outstanding bonds less attractive. If interest rates decline, however, bond prices usually increase, which means an investor can sometimes sell a bond for more than face value, since other investors are willing to pay a premium for a bond with a higher interest payment. The longer a bond’s maturity, the greater the impact a change in interest rates can have on its price. If you’re holding a bond until maturity, interest rate risk is not a concern.

Inflation risk - Like all bonds, corporate bonds are subject to inflation risk. Inflation may diminish the purchasing power of a bond’s interest and principal.

Foreign risk - In addition to the risks mentioned above, there are additional considerations for bonds issued by foreign governments and corporations. These bonds can experience greater volatility, due to increased political, regulatory, market, or economic risks. These risks are usually more pronounced in emerging markets, which may be subject to greater social, economic, regulatory, and political uncertainties.

Credit and default risk - While MBS backed by GNMA carry negligible risk of default, there is some default risk for MBS issued by FHLMC and FNMA and an even higher risk of default for securities not backed by any of these agencies, although pooling mortgages helps mitigate some of that risk. Investors considering mortgage-backed securities, particularly those not backed by one of these entities, should carefully examine the characteristics of the underlying mortgage pool (e.g. terms of the mortgages, underwriting standards, etc.). Credit risk of the issuer itself may also be a factor, depending on the legal structure and entity that retains ownership of the underlying mortgages.
Interest rate risk - In general, bond prices in the secondary market rise when interest rates fall and vice versa. However, because of prepayment and extension risk , the secondary market price of a mortgage-backed security, particularly a CMO, will sometimes rise less than a typical bond when interest rates decline, but may drop more when interest rates rise. Thus, there may be greater interest rate risk with these securities than with other bonds.

Prepayment risk - This is the risk that homeowners will make higher-than-required monthly mortgage payments or pay their mortgages off altogether by refinancing, a risk that increases when interest rates are falling. As these prepayments occur, the amount of principal retained in the bond declines faster than originally projected, shortening the average life of the bond by returning principal prematurely to the bondholder. Because this usually happens when interest rates are low, the reinvestment opportunities can be less attractive. Prepayment risk can be reduced when the investment pools larger numbers of mortgages, since each mortgage prepayment would have a reduced effect on the total pool. Prepayment risk is highly likely in the case of MBS and consequently cash flows can be estimated but are subject to change. Given that, the quoted yield is also an estimate. In the case of CMOs, when prepayments occur more frequently than expected, the average life of a security is shorter than originally estimated. While some CMO tranches are specifically designed to minimize the effects of variable prepayment rates, the average life is always at best, an estimate, contingent on how closely the actual prepayment speeds of the underlying mortgage loans match the assumption.
Extension risk - This is the risk that homeowners will decide not to make prepayments on their mortgages to the extent initially expected. This usually occurs when interest rates are rising, which gives homeowners little incentive to refinance their fixed-rate mortgages. This may result in a security that locks up assets for longer than anticipated and delivers a lower than expected coupon, because the amount of principal repayment is reduced. Thus, in a period of rising market interest rates, the price declines of MBS would be accentuated due to the declining coupon.

Liquidity - Depending on the issue, the secondary market for MBS are generally liquid, with active trading by dealers and investors. Characteristics and risks of a particular security, such as the presence or lack of GSE backing, may affect its liquidity relative to other mortgage-backed securities. CMOs can be less liquid than other mortgage-backed securities due to the unique characteristics of each tranche. Before purchasing a CMO, investors should possess a high level of expertise to understand the implications of tranche-specification. In addition, investors may receive more or less than the original investment upon selling a CMO.

Lower-quality debt securities generally offer higher yields, but they also involve greater risk of default or price changes due to potential changes in the credit quality of the issuer. As well, any fixed income security sold or redeemed prior to maturity may be subject to loss.