The daily price of medium sour crude at the US Gulf coast
The ARGUS Sour Crude Index™ (ASCI™) daily price indexes reflect medium sour crude at the US Gulf coast trading hub, and are used primarily by Saudi Arabia, Iraq and Kuwait to price exports to the US. The indexes come in two forms, both harnessing the liquidity of the Nymex light sweet crude contract and active physical trading for competing coastal medium sour grades in the US Gulf coast:
ASCI = the volume-weighted average of the day’s differential trades for Mars, Poseidon and Southern Green Canyon + Nymex Month 1 settlement price
ASCI 2 = the volume-weighted average of the day’s differential trades for Mars, Poseidon and Southern Green Canyon + Nymex CMA + Argus WTI differential to CMA
Both indexes are available as part of the Argus Crude service under codes PA0006594 (ASCI) and PA0030676 (ASCI 2).
Since its inception in 2009, the physical volume of trades reported for ASCI has grown to around 500,000 b/d. The ASCI market is active and diverse, with about 30 market participants and no single entity accounting for more than 21% of the total trade volume, as of August 2020.
ASCI 2 also utilizes the volume-weighted average of highly-liquid US Gulf coast medium sour grades but adjusted with the Nymex CMA and Argus WTI differential to CMA (“WTI diff to CMA”).
Nymex CMA: Because the front-month futures contract can be more volatile than future months, some companies involved in the USGC sour crude market have asked for a version of the ASCI outright price that is determined using the ratio of month 2 and month 3 and Argus Diff to CMA, rather than on the front month Nymex settle.
The Nymex CMA is comprised of Month 2 and Month 3 Nymex futures settlements prices that provide a projected future value based on today’s settlement prices.
WTI diff to CMA: The Argus WTI diff to CMA is the spread between the projected CMA front month value and the current front month price in the physical WTI market. Throughout the day, the market trades the difference between the CMA futures and the actual physical price for crude to be delivered at a specific future period.
Historical price performance
ASCI 2 was introduced on August 26, 2020, but in using the methodology to calculate back from the start of the year, the prices would’ve tracked similarly except when the futures market strayed significantly from the physical market.