Treasury yields on 30-year US government bonds have climbed to their highest level in nearly two decades as escalating tensions between the United States and Iran continue to destabilize global markets. The surge in long-term borrowing costs reflects investor concerns about geopolitical risk and its impact on the economy.
Rising yields mean the US government faces higher costs to finance its long-term debt. When yields increase, bond prices fall, and the government must offer higher interest rates to attract buyers. The 30-year yield has not reached this level since 2007, before the financial crisis.
Energy prices have driven much of the market upheaval. US gas prices this month are the highest ever recorded for August, with the national average at $4.06 per gallon as of Monday, according to AAA data. This represents a $1 increase from a year ago. In California and Hawaii, prices have reached approximately $5.50 per gallon.
The high energy costs stem from the US-Israel war with Iran that began at the end of February. The conflict has disrupted the Strait of Hormuz, a critical waterway through which a fifth of the world's oil passes. Brent crude, the global oil benchmark, reached $112 per barrel in March, the highest level since 2022. While prices have since declined to around $85 per barrel, they remain about 30 percent higher than a year ago.
Gas prices had dipped briefly after the US and Iran reached initial peace deals, but have climbed again as diplomatic efforts have stalled. On Monday, both countries missed their 60-day diplomatic deadline to end the war after failing to agree on Iran's nuclear program. President Trump has indicated he is not pressuring for quick resolution, stating "I have no time schedule. I'm not in a hurry."
Higher energy costs fuel inflation, which typically pushes bond yields higher as investors demand greater returns to compensate for reduced purchasing power. Treasury yields serve as benchmarks for borrowing costs across the entire economy, affecting mortgages, corporate debt, and consumer loans.
Global bond markets have experienced widespread selling pressure, with yields on government debt in multiple countries reaching multi-decade highs. Stock markets have also declined, reflecting heightened uncertainty about the economic outlook.
Over the past six months of war, Americans have paid an excess of $56.4 billion in elevated gas prices, or approximately $477 per household, according to the congressional Joint Economic Committee. Meanwhile, major oil companies have recorded substantial profits. Eight of the largest oil companies accumulated $90 billion in profits during the first full financial quarter after the war began in March through June, generating roughly $700,000 in profit every minute during that period.
The combination of rising yields and falling stock prices signals growing concern about economic consequences as the geopolitical situation remains unresolved.