What Are Bonds and How Do They Actually Work?
A bond is essentially an IOU with a fixed payment schedule. Here's how lending money to a government or company actually works as an investment.
Lending money, formalized
When you buy a newly issued bond, you're lending money directly to whoever issued it — a national government, a city, or a corporation. In exchange, the issuer agrees to a specific deal: pay you regular interest, called a coupon, on a fixed schedule, and return the original amount you lent, called the face value or principal, on a specific future date called maturity.
This is fundamentally different from buying a stock. A stockholder owns a piece of the company and has no guaranteed payment. A bondholder is a creditor — someone the company or government owes money to — with a contractual right to specific payments, regardless of how the business performs, unless it can't pay at all.
The three numbers that define a bond
Every bond can be described with three core figures: its face value (typically $1,000 for many bonds, the amount repaid at maturity), its coupon rate (the fixed annual interest rate paid on that face value), and its maturity date (when the principal is repaid). A 10-year bond with a $1,000 face value and a 4% coupon pays $40 a year, split into regular installments, until it matures and returns the $1,000.
Why bond prices move at all
If a bond pays a fixed amount, why does its price change once it starts trading in the secondary market? Because interest rates elsewhere in the economy keep changing, and a bond's fixed payments become more or less attractive by comparison. If new bonds start being issued at higher interest rates, an older bond paying a lower fixed rate becomes less appealing — so its price falls until its effective yield, the return based on its current price, lines up with what's available elsewhere. The reverse happens when rates fall.
- Bond prices and yields move in opposite directions — one of the most important relationships in fixed income.
- A bond bought at a discount (below face value) has a yield higher than its stated coupon rate.
- A bond bought at a premium (above face value) has a yield lower than its stated coupon rate.
The risks that come with lending
Bonds are often described as "safer" than stocks, and on average they have been less volatile — but they carry their own real risks. Credit risk is the chance the issuer can't make its payments at all; this is why bonds from financially weaker companies or governments pay higher coupons, to compensate lenders for taking on more risk. Interest rate risk is the chance that rising rates reduce the market value of bonds you already hold, since new bonds now offer more attractive payments.
A bond isn't a guarantee of profit — it's a contract. The value of that contract still moves with the market, even though the payments themselves are fixed.
Where bonds fit in a portfolio
Because bond payments are contractual and often less correlated with stock prices, many investors hold bonds to reduce a portfolio's overall swings and generate steadier income, accepting lower long-run expected returns than stocks in exchange for that stability. How much to hold generally depends on how soon the money might be needed and how much volatility an investor can comfortably sit through.
This article is educational and general in nature. It isn’t personalized investment, tax, or legal advice — always weigh your own circumstances, or talk to a licensed professional, before making financial decisions.