28/09/2026
Monday Money Talk with Noel Whittaker
Suddenly the bond market is grabbing headlines. World debt is soaring, tensions in Iran and Ukraine are intensifying, and a market most Australians rarely think about is becoming impossible to ignore.
And the numbers are staggering. At around US$160 trillion, the global bond market is the biggest financial market in the world, slightly larger than all the world’s listed sharemarkets combined. More importantly, what happens there affects your mortgage, your superannuation, your shares and property, the Australian dollar and ultimately even your taxes. So it’s worth understanding what all the fuss is about.
In this context, a bond is simply an IOU from a government or corporation. It promises investors a capital sum at some future date, together with interest along the way. Take two Australian Government bonds. One pays just 1% and matures on 21 November 2031; the other pays 5% and matures on 21 June 2036.
This is where bonds get interesting. Take the 2031 bond. It pays just $100 a year on a face value of $10,000. With market rates around 5%, who in their right mind would pay $10,000 for something yielding just 1%?
Nobody — and that’s the point. Bonds are liquid investments, and their prices rise and fall with the market. When market interest rates rise, the price of an existing bond falls until its return becomes competitive. Today you might pay roughly $8,200 for that $10,000 bond. You still receive the $100 annual interest, but when it matures in 2031 the government pays you the full $10,000. That $1,800 difference is part of your return.
Now compare it with the 2036 bond paying 5%, or $500 a year on $10,000. Because that is close to today’s market rate, its price stays around $10,000. That’s the golden rule of bonds: when interest rates rise, existing bond prices fall; when rates fall, bond prices rise. Don’t confuse the coupon with the return. A bond paying 1% can still give a new buyer a return approaching 5% because its price has fallen. The government doesn’t alter the interest rate as rates change. It’s the market that alters the price.
Investors are demanding more to lend governments money. Inflation remains stubborn and geopolitical uncertainty remains high, but the elephant in the room is debt. Governments are spending more than they receive and borrowing the difference. US government debt has passed US$40 trillion, while global public debt is heading towards 100% of world GDP by 2029. Somebody has to fund it, and lenders are saying: fine — but you’ll have to pay us more.
And this is where the bond market flexes its muscles. Governments control taxation and spending, while central banks control official short-term interest rates, but neither can completely control the bond market. If investors believe a government is borrowing too much, spending recklessly or allowing inflation to get out of control, they can refuse to buy its bonds at existing prices. Prices fall and yields rise until buyers return. It is the financial markets imposing their own discipline on governments.
US Treasury Secretary Scott Bessent recently threw down the gauntlet to financial markets. Speaking about US intervention to support the Japanese yen, he declared: “I am the house now … And you can bet against me if you want.” The remark has attracted particular attention in bond markets because the US Treasury has also been stepping up its purchases of longer-dated government bonds in an attempt to restrain yields.
Bessent, of all people, should understand the danger of that challenge. In 1992 he was part of George Soros’s team when it took on the Bank of England, betting that Britain could not continue defending the pound. The government fought back, even announcing interest rates as high as 15%, but the market won. Britain was forced out of the European Exchange Rate Mechanism on Black Wednesday, and the Soros fund made more than US$1 billion from its bet against sterling.
Bessent has now changed sides. The trader who helped take on the house is running the US Treasury and declaring that he is the house. But his former boss and mentor Stanley Druckenmiller has a brutally simple warning about governments taking on markets: ultimately, “they always lose”.
Perhaps the best description of the bond market’s power came from James Carville, political adviser to Bill Clinton. He famously said that if reincarnation existed, he wanted to come back as “the bond market. You can intimidate everybody.” Thirty years later, governments may be rediscovering exactly what he meant.
The United States is particularly important because US Treasury bonds are the benchmark for much of the world’s debt. When the US 10-year Treasury yield heads towards 5%, investors naturally ask why they should accept substantially less elsewhere. That matters enormously to Australia. The Reserve Bank sets the cash rate, but it does not dictate interest rates for the next 10, 20 or 30 years. Those are determined by financial markets and reflect inflation, economic growth, expectations about future Reserve Bank decisions and, crucially, what is happening overseas. The bond market can tighten financial conditions without the Reserve Bank doing a thing.
Homeowners should take notice. Variable mortgage rates are heavily influenced by the cash rate, but banks obtain money from many sources, and their wholesale funding costs and fixed-rate loans are influenced by bond and swap markets. Investors should take notice too. When interest rates were close to zero, investors seeking income were virtually forced into shares, property and other riskier assets. Now shares and property have competition. Why take substantial risk for a 4% income return if you can get around 5% from a high-quality government bond?
There is a sting in the tail. If you already own a bond paying 2% and new bonds offer 5%, nobody will pay full price for yours. Its price must fall until its return becomes competitive. That is why supposedly conservative bond funds can suffer capital losses when interest rates rise. But for retirees and other income investors, the flip side is attractive: new money invested in fixed interest can now earn returns unimaginable just a few years ago.
Australia is also a major borrower. There is close to $1 trillion of Australian Government Securities on issue, and around half of Australian Treasury Bonds are held by overseas investors. We therefore depend heavily on international investors continuing to lend us money. If they demand higher returns, we have to pay them. In 2020, Australian 10-year government bond yields fell to barely half of 1%. Today they are around 5%. That is an extraordinary change.
The bond market may seem remote from everyday life, but it sets the price of money. It influences what governments and businesses pay to borrow, what banks charge their customers and how investors value almost every other asset. Governments can keep borrowing only while investors are prepared to keep lending. And those investors are becoming restless.
Perhaps Carville had it right all along: the bond market can intimidate everybody. Right now it is sending a warning — the days of virtually free money are over.