Updates with closing prices for 5 March.
US Gulf deepwater Mars crude rose to $7/bl over second-month Ice Brent Thursday, gaining about $5/bl from Wednesday and reaching a third consecutive six-year record premium to the US benchmark because of Middle Eastern crude and products supply disruptions.
The Louisiana-delivered medium sour traded at a $7/bl premium to April Domestic Sweet (DSW) on Thursday, as buyers sought to secure alternative supply to Middle Eastern imports that are essentially cut off by the war in the region, given the effective closure of the strait of Hormuz. Thursday's volume-weighted average was $2.60/bl higher than on 3 March, when Mars hit its highest premium to the DSW basis since April 2020 for the first time this week.
The Argus April Mars outright price assessment was $88.01/bl, putting it at around a $7/bl premium to June Ice Brent as it settled around parity to April Nymex WTI, which reflects the DSW value. April Mars has firmed by $5.20/bl relative to June Ice Brent from the prior session and by more than $11/bl from 27 February, ahead of the US-Israeli attacks on Iran.
Middle Eastern crudes accounted for about 24pc of all US waterborne crude imports from November 2025 to February 2026, according to analytics platform Vortexa, or 587,000 b/d. Of the 277,000 b/d delivered to the US Gulf coast in that time, about 95pc was medium sour.
Export interest for Mars has picked up despite high freight rates as refiners globally seek to secure reliable replacement supply. A Japanese refiner was heard buying Mars this week and Indonesia has announced they are looking to shift to other crude sources, including the US. Most of Indonesia's Middle Eastern crude imports are Saudi Arabia medium sours.
