Archive · 18 Aug 2026
US-Iran truce expires as oil rises, bond yields climb
The United States and Iran had a temporary agreement to stop fighting, but it ended because they could not agree on a new deal.
Iran said it would get ready to fight if talking did not work.
This made people worried that oil ships might not be able to travel through a very important waterway called the Strait of Hormuz.
Because of this worry, the price of oil went up.
A barrel of Brent crude oil cost about $91.
Fewer oil tankers are going through the strait now.
Higher oil prices can make things cost more for everyone.
People who buy government bonds also got nervous, so bond prices changed and their yields went up.
The US 30-year bond yield reached its highest level in more than 20 years.
Stock markets in Asia were mixed, with some going up and some going down.
Everyone is watching to see if the US and Iran can start talking again.
The temporary US-Iran ceasefire expired after diplomatic efforts failed to produce a breakthrough.
Brent crude rose 0.2% to $91.06 a barrel, while WTI hit its highest level since late July.
Only five tankers passed through the Strait of Hormuz on Saturday and none on Sunday, versus 31 the previous weekend.
The US 30-year Treasury yield climbed to 5.3146%, its highest level in more than two decades.
Asian stocks were mixed, with South Korea's KOSPI jumping over 3% while Japan's Nikkei 225 fell 0.3%.
- Who
- The United States and Iran, whose temporary ceasefire expired, along with global investors and markets.
- What
- The truce expired, oil prices rose and government bond yields climbed on renewed supply concerns.
- When
- Tuesday, after the ceasefire expired following failed diplomatic efforts.
- Where
- Global markets, with focus on the Strait of Hormuz, the US, Japan and Asian markets.
- Why
- Failed US-Iran diplomacy revived fears of conflict and disruption to oil shipping through the Strait of Hormuz.
- Brent crude price
- $91.06 per barrel (up 0.2%)
- US 10-year Treasury yield
- 4.728% (up 0.8 basis point)
- US 30-year Treasury yield
- 5.3146% (up 0.6 basis point), highest in over two decades
- Japan 10-year JGB yield
- 2.945% (up 2.5 basis points), highest in three decades
- Tankers through Strait of Hormuz
- 5 on Saturday, 0 on Sunday, vs 31 previous weekend
- KOSPI
- Rose more than 3% after holiday reopening
- Nikkei 225
- Fell 0.3%
- S&P 500 (Monday)
- Slipped 0.5%