Fixed Income Explained: How Bonds Work and Why Rates Matter

If equities make you an owner, bonds make you a lender, and that single difference explains almost everything about how the two asset classes behave. As a lender, you do not share in a company's runaway success, but you do sit ahead of shareholders in the queue to be paid, and you receive a predictable stream of interest. That predictability is why bonds, the popular name for the fixed-income asset class, are the traditional ballast of a portfolio. But bonds are widely misunderstood, especially the counter-intuitive way their prices move. This article demystifies them.

The basics

A bond is a loan. When a government or company needs to borrow, it can issue bonds: IOUs sold to investors. In return for your money, the issuer promises two things:

• Regular interest payments (the "coupon"), usually fixed, hence "fixed income."
• Repayment of the original sum (the "principal" or "face value") on a set future date (the "maturity").

Lend £1,000 to a government via a 10-year bond with a 4% coupon, and you receive £40 a year for ten years, then your £1,000 back. That known schedule is the source of bonds' relative stability and their appeal to investors who want income and lower volatility than equities.

The main types of bond, roughly from safest to riskiest:

• Government bonds: issued by national governments. UK government bonds are "gilts," US ones are "Treasuries," German ones "Bunds," French ones "OATs." Bonds from stable governments are considered very low-risk.
• Investment-grade corporate bonds: issued by financially solid companies, slightly riskier than governments, paying a little more.
• High-yield ("junk") bonds: issued by weaker companies, higher interest to compensate for a real risk of default.

The global bond market is vast, larger, in fact, than the global equity market, because governments and companies the world over rely on borrowing.

Going deeper

The most important idea: bond prices move opposite to interest rates. This trips up almost every beginner, so it is worth slowing down. Once a bond is issued with a fixed coupon, that coupon never changes. But new bonds are constantly issued at whatever the current interest rate is. So:

• If interest rates rise, newly issued bonds pay more, making your older, lower-paying bond less attractive. To sell it, you must drop the price. Rates up, existing bond prices down.
• If interest rates fall, your older bond's higher coupon looks attractive, so its price rises. Rates down, existing bond prices up.

This inverse relationship is the master key to fixed income. It means bonds are not risk-free even when default is not a worry: their market value swings with interest rates. In 2022, when central banks raised rates sharply to fight inflation, even "safe" government bonds fell heavily, a painful surprise for investors who thought bonds couldn't lose money.

Yield is the other half of the language. A bond's yield is the return it offers at its current price, and because price and yield move inversely, "yields rising" and "prices falling" describe the same event. When you hear that bond yields have risen, bond holders have just taken a capital hit, but new buyers can now lock in higher income.

Duration measures the sensitivity. How much a bond's price moves when rates change depends largely on its duration, broadly, how far in the future its payments arrive. A long-dated bond (say 30 years) is highly sensitive: a small rate change swings its price a lot. A short-dated bond (say 2 years) barely moves. Matching duration to your time horizon and risk tolerance is the central craft of bond investing: reach for the higher yield of long bonds and you accept bigger price swings.

The rate environment of 2026. Context matters here. After the steep rate rises of 2022–2023, major central banks spent 2024–2025 cutting rates, and as of mid-2026 policy rates across major economies sit in a moderate band, broadly the low-single-digit-percent range, having come down from their peaks, though the path ahead is clouded by renewed geopolitical and inflation uncertainty. The practical point for a bond investor is not the precise rate on any given day (which changes constantly and should be checked live) but the principle: today's bonds offer meaningfully more income than the near-zero yields of the 2010s, which has restored bonds' traditional role as a genuine source of return and ballast.

Why hold bonds at all? Three reasons. They provide income that is more predictable than dividends. They offer stability, high-quality bonds are far less volatile than equities. And they can provide diversification: historically, government bonds have often risen when equities fall (investors flee to safety), cushioning a portfolio, though, as the final article warns, this negative correlation is not guaranteed and broke down in 2022 when both fell together. In practice, most investors get bond exposure through low-cost bond ETFs rather than buying individual bonds.

Credit risk versus interest-rate risk. Bonds carry two distinct risks. Interest-rate risk is the price sensitivity just described, dominant for government bonds. Credit risk is the chance the issuer fails to pay, dominant for corporate and especially high-yield bonds. A government bond fund is mostly an interest-rate bet; a high-yield fund is largely a credit bet that behaves more like equities than like "safe" bonds.

Common mistakes

• Thinking bonds can't lose money. Their prices fall when rates rise. 2022 was a hard lesson that even government bonds carry real interest-rate risk.
• Ignoring duration. Reaching for the higher yield of long-dated bonds without realising how violently their prices can swing is a common and costly error. Match duration to your horizon.
• Treating all bonds as "safe." High-yield bonds carry substantial default risk and behave more like equities. The label "bond" spans a wide risk spectrum.
• Misreading "yields up" as good news for holders. Rising yields mean falling prices for bonds you already own, even though new money can now earn more.
• Expecting bonds to always offset equities. The cushioning effect is historical tendency, not law. In 2022 both fell together. Diversification across more than two classes matters.

FAQ

Why do bond prices fall when interest rates rise? Because a bond's coupon is fixed at issue. When new bonds pay more, your older, lower-paying bond is worth less, so its market price falls until its yield matches the new environment.

Are government bonds risk-free? From a default standpoint, bonds from stable governments are very low-risk. But they still carry interest-rate risk, their market value falls when rates rise, as 2022 demonstrated.

What is duration? A measure of how sensitive a bond's price is to interest-rate changes, driven mainly by how far in the future its payments fall. Longer duration means bigger price swings for a given rate move.

Why hold bonds if equities return more? For income, stability, and diversification. Bonds reduce a portfolio's overall volatility and have often (though not always) risen when equities fall, helping you stay invested through downturns.

The takeaway

Bonds make you a lender, exchanging the upside of ownership for predictable income and a place nearer the front of the repayment queue. The one idea to carry away is that bond prices move opposite to interest rates, which is why even default-free government bonds can lose value, as 2022 proved, and why duration is the lever that controls how much. After the rate rises and falls of recent years, bonds in 2026 once again offer real income and a meaningful diversifying role, just not a guaranteed one. Next, we look at the safest, simplest class of all, and the baseline against which every other is measured: cash.

Educational not advice

This article is for general educational purposes only and is not financial or investment advice. It does not consider your circumstances. Bond values fall as well as rise, and issuers can default. Interest rates and yields change continually and current figures should be verified. Consider advice from a regulated professional before investing.

Sources

• Bank of England, US Federal Reserve, ECB: policy rate data (2026)
• SIFMA and Mordor Intelligence, global bond market size (2026)
• Morningstar, research on duration, credit risk, and the 2022 bond drawdown
• DMO and US Treasury, primers on government bond mechanics