Government bond yields: Why prices fall when interest rates rise

The yield on ten-year US government bonds rose to 5.31% in October 2026 (closing value on 5 October, US Treasury). Reports citing different figures (5.34%, 5.29%, 5.36%) speak of the highest level since 2002. By 21 October it had fallen to 5.13%. Past yields and prices are not a reliable indicator of future results.

When the yield rises, the price of the bond falls. A numerical example further down shows why. Data as of: 21 October 2026.

Why do bond prices fall when interest rates rise?

A comparison helps. Suppose (illustration) someone holds a bond with a 2% coupon. New bonds pay 5%. The old bond only finds a buyer if its price falls. Only then is it equivalent to the new bonds. This is how the yield rises and the price falls.

In the example, the longer the remaining term, the more strongly the price reacts. The reason is that the bond stays tied to the low coupon for longer. When the yield falls, the reverse happens and the price rises.

Anyone who holds the bond until repayment receives the nominal value back in the example, provided the debtor pays. The price loss then does not show up as a loss on sale. However, investors remain tied to the lower coupon until maturity, and currency and credit risk remain.

What happened in October 2026?

The US Treasury publishes the 10-year yield daily. It is based on indicative quotations collected by the Federal Reserve Bank of New York at around 3:30 pm New York time, not on actual trades. It is therefore a daily close and not an intraday high.

On 1 October the yield stood at 5.24%. On 5 October it reached 5.31%, the highest for the month up to 21 October. On 8 October it was 5.22%. After that it moved mostly downwards. On 16 October it stood at 5.09%, 0.22 percentage points below the high. The largest daily move came from 14 to 15 October (5.19% to 5.10%). The most recent values were 5.15% (19 October), 5.12% (20 October) and 5.13% (21 October).

During trading the yield was at times higher. According to Admiral Markets, it rose to 5.36% on 7 October, the highest level since April 2002 (figure from Bloomberg). This is a value reached temporarily during trading, not a closing value. The Treasury closing value that day was 5.28%.

Other reports cite other figures again. dpa reported 5.34% on 1 October, and Börsen-Zeitung 5.29% on 8 October. Both speak of the highest level since 2002. The values differ partly because the timing and data providers are different.

Past yields and prices are not a reliable indicator of future results.

What drove the yield, according to reports?

The reports cite several reasons. None of them is established.

• Inflation and oil: dpa cites inflation concerns due to rising oil prices in connection with the Iran war. Börsen-Zeitung reported on 8 October that Brent crude had risen by almost 4% to 104 US dollars per barrel.
• Sales of older bonds: According to dpa, investors are selling older bonds, causing their prices to fall.

What are the risks and limitations?

• Interest rate risk: If interest rates rise, the prices of existing bonds can fall, as in the numerical example.
• Selling before repayment: Anyone who sells early bears the price loss or gain. Anyone who holds until maturity is tied to the lower coupon, and currency and credit risk remain.
• Debtor: Lending money means bearing the risk that the debtor does not pay. The article on Lehman certificates 2008 shows what effects a default can have.
• Currency: US government bonds are denominated in US dollars. Investors who measure returns in Swiss francs bear the risk of fluctuating exchange rates.
• Measurement: "Highest level since 2002" only applies until a higher value is reached. Closing value and intraday peak are different figures.
• Reports: The reasons cited are the assessments of the reports, not established causes. The article on diversification explains how risks can be spread across several investments.

Past yields and prices are not a reliable indicator of future results.

What dates are coming up?

The Federal Open Market Committee of the Federal Reserve (Fed, the central bank of the United States) meets on 27 and 28 October 2026. The Governing Council, the decision-making body of the European Central Bank, meets on 28 and 29 October 2026, with the press conference on 29 October. These are dates only, not an expectation about the outcome.

Conclusion

According to the Treasury closing value, the yield on ten-year US government bonds reached 5.31% in October 2026 and stood at 5.13% on 21 October. The intraday peak of 5.36% on 7 October is a different measure. Rising yields mean falling prices for existing bonds, and falling yields mean rising prices. The reasons cited come from reports and are not established. Past yields and prices are not a reliable indicator of future results.