Bonds for Beginners: Lending, Interest, and Risk Explained

A bond is a loan, not a share of ownership. When you buy a bond, you lend money to the issuer — a government, a company, or another borrower — and the issuer promises to pay you interest for a set period and return the principal when the bond matures. That promise, and how much it is worth if you need to sell early, is the whole subject of this guide.

A bond is a loan with written terms

Buying a stock makes you a part-owner. Buying a bond makes you a lender. The issuer gets money now and owes you scheduled payments later. You do not get a vote in how the issuer is run, and you do not share directly in its profits beyond the interest it promised. In return, your claim usually ranks ahead of shareholders if the issuer runs into trouble — ahead does not mean guaranteed, as the risks below show.

Four terms define a plain bond. Face value, also called par value, is the principal the issuer promises to repay at maturity. The coupon rate is the annual interest rate stated as a percentage of face value. Maturity is the date the principal comes back. The issuer is who owes you the money. Read those four before anything else, because they set every payment that follows.

A worked example: a $1,000 bond at 4% for 10 years

Take a bond with a $1,000 face value, a 4% coupon, and a 10-year maturity. It pays $40 a year in interest, typically as $20 every six months. If you hold it to maturity and the issuer pays as promised, you receive those interest payments plus the $1,000 principal at the end of the 10 years. This matches the example in the U.S. Securities and Exchange Commission's investor bulletin on corporate bonds, which uses the same $1,000, 4%, and semiannual pattern.

Two cautions belong with that example. First, the $40 a year is fixed by the coupon; it does not rise because other rates rise. Second, getting the principal back at maturity depends on the issuer still being able to pay. Holding to maturity removes the risk of selling at a bad price, but it does not remove default risk.

Why a bond's price moves when interest rates move

A bond can be sold before maturity, and its market price moves in the opposite direction from interest rates. Suppose market rates rise after your 4% bond is issued, and new bonds now pay more. A buyer has little reason to pay full price for your older, lower-coupon bond, so its price falls until its yield — the return measured against the price actually paid — looks competitive again. If market rates fall instead, your fixed 4% coupon looks better than new issues, and the price can rise above face value.

That gives three price words worth knowing. A bond trading at face value is at par. Above face value is a premium. Below face value is a discount. The coupon never changes with the price; the yield does. A premium bond pays the same coupon but costs more, so its yield is lower. A discount bond costs less for the same coupon and principal, so its yield is higher — compensation for buying a bond whose coupon now looks low.

Longer maturities usually swing more. A 30-year bond has many more fixed payments exposed to rate changes than a bond maturing next year, so the same rate move tends to change its price by more. If you might need the money before maturity, that price swing matters. If you can hold to maturity, the interim price matters less, because the promised payments and principal are what you are waiting for.

Who issues bonds, and how the types differ

Government bonds are issued by national governments. In the United States, TreasuryDirect lists Treasury bills with terms from 4 weeks up to 52 weeks, Treasury notes with maturities of 2, 3, 5, 7, and 10 years, and Treasury bonds in 20-year and 30-year terms. Notes and bonds pay interest every six months; bills are sold at face value or at a discount and pay face value at maturity, with no regular interest payments. These securities are backed by the full faith and credit of the U.S. government.

Corporate bonds are issued by companies, and municipal bonds by states, cities, and other public bodies. The issuer's credit strength is the key difference: a government with taxing power, a large stable company, and a smaller borrower do not carry the same risk of missing a payment, and the market charges different yields to reflect that. This guide names the types only to explain the structure; it does not recommend any issuer, bond, or fund.

The risks that remain after the promise

Credit risk, also called default risk, is the risk the issuer fails to pay interest or principal on time, or at all. Interest-rate risk is the price fall described above when rates rise before you sell. Inflation risk is quieter: fixed coupon payments buy less over time if prices rise, so a bond that looks steady in dollars can still lose purchasing power. There is also reinvestment risk — when a bond matures or is called early, the money may have to be reinvested at lower rates than before.

Bond funds add one more distinction. An individual bond has a maturity date when principal comes back, assuming the issuer pays. A bond fund has no single maturity date; it holds many bonds, its price moves daily, and its value at any moment reflects the market prices of what it holds. The same interest-rate logic applies, but there is no date on which you are promised your original amount back.

A short checklist before you buy

• Who is the issuer, and what is backing the promise to pay?
• When does the bond mature, and does that date fit when you need the money?
• What is the coupon, and what yield do you actually get at the price you would pay?
• What happens if you sell before maturity — could the price be below what you paid?
• If you are buying through a fund, what does it hold, what does it charge, and is there a single maturity date? No, there is not, and that changes what "getting your money back" means.

Bonds are often described as the steady part of a portfolio, and compared with stocks they usually move less day to day. Steady is not the same as safe in every sense. A bond can lose market value, lose purchasing power, or, in the case of a weaker issuer, fail to pay. The useful question is not whether bonds are safe in general, but whether a specific bond's issuer, maturity, and price fit the job you want it to do. This guide is educational only, not personal financial advice. For advice about your own situation, speak with a qualified financial professional.

Sources

• U.S. Securities and Exchange Commission, Investor Bulletin on corporate bonds: https://www.sec.gov/files/investor/alerts/ib_corporatebonds.pdf
• TreasuryDirect, About Treasury Marketable Securities: https://treasurydirect.gov/marketable-securities/