Bonds Explained

A bond is a loan investors make to a government or company in exchange for regular interest and the return of principal. The bond market that trades those loans is bigger than the stock market, and it sets the price of money itself.

A bond is just a loan with paperwork

When an investor buys a bond, they are lending money to the issuer — a government, a municipality, or a corporation — for a fixed period. In return, the issuer promises two things: regular interest payments, called the coupon, and the return of the original amount, the principal or face value, when the bond matures. A ten-year U.S. Treasury bond, for instance, pays interest twice a year and returns the full principal a decade after issuance.

This is fundamentally different from owning stock. A bondholder has no claim on the company's growth and no vote in its decisions, but they sit ahead of shareholders in the pecking order if the issuer runs into trouble, and their payments are contractually fixed rather than dependent on how profitable the business turns out to be.

Why issuers borrow this way

Governments issue bonds to fund spending that tax revenue alone does not cover — infrastructure, defense, social programs, or simply rolling over debt that is coming due. Because governments can tax and, in the case of countries that borrow in their own currency, control the money supply, their bonds are generally considered lower risk than corporate debt, which is why U.S. Treasuries serve as the benchmark risk-free rate against which nearly everything else is priced.

Companies issue bonds as an alternative to issuing new stock or borrowing from a bank. Debt is often cheaper than equity because interest payments are tax-deductible and bondholders demand a lower return than shareholders in exchange for taking less risk. The trade-off is that interest payments are a fixed obligation — miss one and the company can be forced into default, regardless of how the stock is doing.

Why bond prices and yields move opposite each other

A bond's price and its yield — the effective return an investor earns — move in opposite directions. If a bond pays a fixed coupon and prevailing interest rates rise, newly issued bonds offer better terms, making the older, lower-paying bond less attractive unless its price falls to compensate. That inverse relationship is the single most important mechanic in fixed income, and it is why central bank rate decisions move bond prices immediately and directly.

Longer-dated bonds are more sensitive to this effect than short-dated ones, because a change in rates compounds over more years of fixed payments. That sensitivity is one reason the yield on the ten-year Treasury is watched so closely — it reflects the market's collective view on where growth and inflation are headed over the next decade.

Why the bond market matters beyond bond investors

Treasury yields function as the foundation for pricing across the entire economy: mortgage rates, corporate borrowing costs, and even how stocks are valued all reference the risk-free rate set in the bond market. When yields rise sharply, it becomes more expensive for companies to borrow and more attractive for investors to hold safe bonds instead of riskier stocks, which is why a fast move in yields often shows up as volatility in equities the same day.