Bonds explained: the "safe" part of your portfolio, why it can still fall, and the role it plays in retirement

Most retirees own bonds without really knowing it — they're tucked inside the "balanced" or "conservative" super option you chose years ago, doing the quiet work of steadying the portfolio. Bonds are the classic defensive asset: lower risk than shares, a source of regular income, and the thing that's meant to hold up when share markets wobble. Yet very few people who hold them could explain what a bond actually is or why its value moves — which is why 2022 came as such a shock, when the "safe" part of people's portfolios fell in value alongside shares. The reason traces back to the single mechanic that defines bonds and that almost nobody is taught: bond prices move in the opposite direction to interest rates. This article explains what a bond is, why its price moves, the crucial difference between holding a bond and holding a bond fund, how bonds compare to cash, and the role fixed income plays in a retirement portfolio. It is general information only, not personal advice.

What is a bond actually?

A bond is essentially a loan you make — to a government or a company. In return, the issuer promises to pay you regular interest (called the coupon) for a set period, and to repay your capital (the face value) on a fixed future date (the maturity). As Australia's government money-guidance service describes it, bonds are fixed-interest investments that pay a set coupon rate for the term and repay the face value at maturity — for example, a $100 bond with an 8% rate pays $8 a year (MoneySmart). You're the lender; they're the borrower. Because the coupon is usually a fixed, scheduled payment, bonds are called "fixed income" — they're designed to deliver predictable income and a return of your capital, unlike shares, which pay variable dividends and never "mature." That predictability, and the lower risk than shares, is why bonds are the traditional defensive building block.

What is the mechanic that surprises everyone?

Here's the part that catches people out. Bond prices move inversely to interest rates. Imagine you hold a bond paying a fixed 3% coupon, and then new bonds start being issued paying 5%. Your 3% bond is suddenly less attractive — so if you wanted to sell it, you'd have to drop the price to tempt a buyer. As MoneySmart puts it, "when interest rates rise, the price of existing bonds typically falls" (MoneySmart). Flip it around: if new bonds pay just 1%, your 3% bond is now more valuable, and its price rises. So the rule is: rates up, bond prices down; rates down, bond prices up. How much the price moves depends on a measure called duration — broadly, the longer the time to maturity, the bigger the price swing for a given change in rates. When interest rates rose sharply in 2022 after years of being very low, bond prices fell, and retirees who believed bonds "can't lose money" got a genuine fright. (That 2022 episode is recent market history, offered as illustration, not a prediction.)

What is the nuance that should calm you down?

If you hold a bond all the way to maturity — and the issuer doesn't default — you get all your coupons and your full face value back, no matter how the price bounced around in between. MoneySmart states it plainly: "If you hold the bond until maturity, you get back the face value (or principal) of the bond. If you sell a bond before maturity, you'll get the market value, which could be lower than the face value" (MoneySmart). So for a hold-to-maturity investor, an interim price fall is a paper loss, not a real one; you simply collect your interest and get your capital back on the maturity date as promised. This distinction — between a price that's fallen on paper and a loss you've actually realised by selling — is central to understanding bonds, and it's widely missed. Which brings us to a difference that matters enormously and that most people don't know.

Is holding a bond the same as holding a bond fund?

Most people (and most super options) don't own individual bonds — they own a bond fund or bond ETF: a diversified, professionally-managed bundle of many bonds, easy to buy. The catch is that a bond fund doesn't mature. It holds a constantly-rolling portfolio of bonds, so there's no single maturity date at which you're guaranteed your capital back — the fund's unit price simply floats up and down with interest rates. So the comforting "hold to maturity and get your money back" feature works differently for a fund: its value moves with rates, which is exactly why people's "defensive" bond funds fell in 2022. (Over time, the fund reinvests at the new, higher rates, which gradually offsets the price fall — but there's no fixed date guaranteeing your capital.) The practical upshot: if you specifically want the certainty of getting a set amount back on a set date, that points to direct bonds or term deposits; if you want diversification and simplicity, a bond fund does that, but you have to accept a floating value.

What are the two risks to keep straight?

Bonds carry two distinct risks. The first is the interest-rate risk we've just covered — price moves with rates — and every bond has it, even the safest. The second is credit risk — the risk the issuer can't pay you back. This varies hugely: government bonds (Commonwealth or state) are considered the lowest credit risk and are the core defensive ballast, because government debt is backed by the taxing power of the government, while corporate bonds carry higher yields precisely because they are riskier — their credit risk is higher (MoneySmart). That credit risk climbs as you move from investment-grade (stronger companies) down to sub-investment-grade or "high-yield" debt (weaker borrowers paying more to compensate — the territory that shades into private credit, covered in a separate article). The tell, as always in investing, is the yield: a bond offering a notably higher yield is generally compensating for higher risk, not handing you a free lunch. Reaching for those higher yields means taking on equity-like risk dressed up as "fixed income."

How do bonds compare to cash and term deposits?

Both bonds and cash sit on the defensive side, but they're not the same. Term deposits and cash are capital-stable and, for bank deposits, government-guaranteed under the Financial Claims Scheme up to $250,000 per account-holder per institution (MoneySmart) — no price risk — but usually offer lower yield and no capital gain if rates fall. Bonds can offer a higher yield and can rise in value if rates fall, and they add diversification — but they carry interest-rate risk (and, for non-government bonds, credit risk), and they're not government-guaranteed. Many retirees sensibly hold both: cash for the near-term buffer they might need to draw on (see our companion piece on where to hold cash in retirement), and high-quality bonds for the longer defensive allocation.

So what is the point of holding bonds in retirement?

Three things. Ballast — bonds typically behave differently from shares and have historically cushioned a portfolio when shares fall, which is the whole rationale behind the classic "growth/defensive" split (think of a "60/40" portfolio). Income — those regular coupons suit a retiree's need for cash flow. And lower volatility than shares — a steadier ride that helps you stay the course and, importantly, lets you fund your income without being forced to sell growth assets at the bottom of a market fall (the same logic behind not switching super to cash in a downturn, covered separately). The honest caveat is 2022, when bonds and shares fell together and the diversification didn't work that year — a reminder that bonds aren't risk-free and the hedge isn't perfect. But over the long run, high-quality bonds' role as ballast and income is why they remain a core part of sensible portfolios. For Centrelink, by the way, bonds and bond funds are deemed financial investments like any other — earning a deemed 1.25% up to the threshold and 3.25% above it (DSS Social Security Guide 4.4.1.10, https://guides.dss.gov.au/social-security-guide/4/4/1/10) — and the coupon interest is assessable income for tax, generally without franking credits.

What do worked examples look like?

These show the two things most retirees get wrong about bonds. They are illustrative only — not personal advice, and past market behaviour is not a prediction.

Hugh, 70, was told his money was in a "conservative" option that was mostly bonds and therefore "safe," so he was alarmed when its value fell noticeably during a year when interest rates jumped. He'd always believed bonds couldn't lose money. On these facts, Hugh has run into the bond mechanic and the fund nuance at the same time. His option fell because rising rates pushed bond prices down — the inverse seesaw — and because he holds bonds through a fund, there's no maturity date at which his capital is guaranteed back; the fund's value simply floats with rates. Had he held individual bonds to maturity, the interim price fall would have been a paper loss and he'd still get his face value back on the maturity dates — but a fund doesn't work that way. Understanding this changes Hugh's reaction from panic to perspective: the fall was a mark-to-market move, not money set on fire, and over time the fund reinvests at the new higher rates. On these facts, if what Hugh actually wants is certainty of a set amount back on a set date (say, for a known future expense), the lesson is that a bond fund isn't the tool — a direct bond or a term deposit is. The label "conservative" was true in the sense of lower risk than shares, but it never meant can't fall, and now Hugh knows why.

Marcia, 68, wants to build the "defensive" part of her portfolio and has been shown two options: a high-quality government/investment-grade bond fund, and a "fixed income" product paying a much higher yield. On these facts, Marcia needs to see that the two are not the same kind of thing, despite both wearing the "fixed income" label. The high-quality bond fund is genuine defensive ballast — low credit risk, there to steady the portfolio and pay income, with the interest-rate price movement we've discussed. The much-higher-yielding product is almost certainly compensating for more risk — lower-grade corporate or high-yield/private credit debt, where the extra yield is the price of default and liquidity risk, not a bonus. If Marcia puts that in her "defensive" sleeve thinking it's safe, she's taken on equity-like risk in the part of her portfolio that's meant to be the safe anchor. On these facts the rational approach is to keep the defensive sleeve genuinely defensive with high-quality bonds (and cash), and if she wants to take more risk for more return, do it knowingly in the clearly-labelled growth part of the portfolio — not by reaching for yield in the bit that's supposed to hold firm when everything else falls. The yield was the clue: more yield, more risk.

The thread is that bonds are worth understanding precisely because you probably already own them. Hold onto a few ideas: a bond is a loan that pays you interest and returns your capital at maturity; its price moves opposite to interest rates (so even "safe" bonds can fall), but a bond held to maturity returns your capital regardless — while a bond fund doesn't mature and so its value floats; government bonds carry interest-rate risk but little credit risk, whereas higher-yield bonds carry real default risk; and bonds belong in the defensive sleeve alongside cash, as ballast and income, not as a risk-free guarantee. Use bonds (or term deposits) for capital certainty where you need it, diversified bond funds for simplicity where you don't, and keep your defensive money genuinely defensive rather than chasing yield down the credit ladder. Because market behaviour is illustrative and not a promise, and the right mix depends on your own situation, get personal advice on how much fixed income you should hold and in what form. Understanding the "boring" part of your portfolio is what stops a normal bond wobble from feeling like a crisis.

Sources

• MoneySmart — Bonds
• MoneySmart — Term deposits
• DSS Social Security Guide 4.4.1.10 — Overview of deeming