Rising US Treasury Yields Signal Strain on Economy and Borrowing Costs

US government borrowing costs have climbed to levels not seen in over 20 years, reflecting growing worries about inflation and the strength of the economy. On 24 September 2026, the yield on 30-year Treasury bonds briefly rose above 5.44%, the highest since 2004, while the 10-year yield reached around 5.12% during the day.

These yields measure the interest the US government must pay to borrow money. When yields rise, it means investors want better returns, often because they expect inflation to rise or see more risk. Higher yields also push up borrowing costs for businesses and consumers alike, including mortgage rates. In fact, 30-year mortgage rates in the US have climbed to about 7%, near a two-year high.

The rise in yields comes amid strong economic growth and persistent inflation pressures. Recent data showed the fastest expansion in business activity since mid-2021, with prices for inputs rising sharply, partly due to higher energy costs linked to ongoing conflicts in the Middle East.

In response to these inflation risks, the US Federal Reserve raised its key interest rate to a range of 3.75% to 4.00% in mid-September and signalled that further hikes may be needed before the end of the year. These moves aim to slow inflation but can also make borrowing more expensive.

The US Treasury has tried to ease market pressure by increasing buybacks of longer-term bonds, but these efforts have not stopped yields from climbing. The combination of strong government spending, robust economic growth, and inflation concerns is making it tougher to manage borrowing costs.

While markets have so far remained calm, the higher yields could test the resilience of global financial markets and start to affect consumers and businesses through more expensive loans and mortgages. How the Federal Reserve balances these pressures will be closely watched in the coming months.