Supply and demand explain much of the oil market, and on Monday 2 November hopes of peace outweighed fears. Bloomberg reported that oil prices fell more than 7%, the largest slump in three months. Earlier that day Reuters had Brent down 1.40% at $111.84 a barrel.
By the close, prices were lower still. West Texas Intermediate futures for December delivery settled about 7.4% lower at $96.46 a barrel, below the $100 mark, and Brent for January settlement dropped 7.6% to close at $104.77.
Diplomacy lay behind the move. Iranian and Qatari officials held a third straight day of talks on Sunday, and Iran's foreign minister, Abbas Araqchi, called them 'ongoing and progressing'. State-run IRNA reported that Iran's supreme leader approved the government pursuing negotiations.
The United States sent signals too. Asked whether he would resume strikes on Iran after Tuesday's vote, US President Donald Trump said 'no', according to a media pool report.
The fall spread beyond oil. Bloomberg reported that European benchmark gas futures fell almost 11% at one point, and that US heating oil had its steepest drop in six months.
Traders called it a release of worry. Darrell Fletcher of Bannockburn Capital Markets said a lot of risk premium was seeping out of crude oil and European natural gas. Brent had ended October at its highest level in six months.
Big problems remain. The two sides have not agreed on terms for fully reopening the Strait of Hormuz, described as the world's most important energy chokepoint, and attacks on tankers there are raising global energy and shipping costs.
Other forces also push prices. Escalating Ukrainian attacks on Russian refineries had pushed fuel prices higher in recent months, and OPEC+ kept December production targets steady on Sunday.
Markets act fast on such news. Kpler's Bridgeton Research Group said trend-following commodity trading advisers cut their Brent long positions, which are bets on rising prices, to 91% from 100% at the start of the session.
Oil is the fuel that moves cars and ships. On Monday 2 November, oil prices fell more than 7%. That was the biggest slump in three months.
US oil closed at $96.46 a barrel. Brent closed at $104.77.
Iran and Qatar held three days of talks to try to end a war. That gave people hope. A trader said some of the worry was seeping out of the market.
But the two sides have not agreed on how to fully reopen the Strait of Hormuz. Attacks on tankers there make shipping cost more.