Platts makes minimum volume, lot size adjustments for US aluminum premium assessments

Platts, part of S&P Global Commodity Insights, has adjusted the minimum volume specification for its US aluminum premium assessments, including the Midwest Transaction Premium, to 100 mt, effective Sept. 1, 2025.

The minimum volume update aligns to the typical volume range of 100-1,000 mt reflected in Platts specifications and with volumes published in transparent bids, offers and trades in the Platts Market on Close assessment process.

Additionally, Platts has introduced incremental volume lot sizes of 20 mt for bids, offers and trades in the MOC after the 100 mt minimum has been reached, also effective Sept. 1, 2025, consistent with typical trading increments observed within the 100-1,000 mt volume range.

Minimum volume

The volume specification reflected in Platts US aluminum premium assessments is now a minimum of 100 mt and a maximum of 1,000 mt, amended from the previous "minimum full 45,000 lb truckloads" (equivalent to around 20 mt). Volumes under 100 mt and above 1,000 mt may be considered for assessment purposes and normalized to the typical specification.

The adjustment impacts the following assessments:

The revised volume specification also applies to associated all-in calculations.

Lot size

Bids, offers and trades reported in the US aluminum MOC are published in multiples of 20 mt above the 100 mt minimum volume specification.

This lot size aligns with the current practice in the physical spot market, and is being added to Platts Market on Close assessment process timing and increment guidelines.

Platts first proposed these adjustments on May 16 in a subscriber note available here.

Platts extended the feedback period for the proposed changes and updated the proposed implementation date on June 25 in a subscriber note found here. Following market feedback, Platts revised the volume lot increment from the 25 mt initially proposed and confirmed the minimum volume update in a subscriber note published Aug. 1, available here.

Platts MOC timing and increments guidelines are available here.

Full US aluminum assessment specifications can be found in Platts non-ferrous metals specifications guide.

The assessments are published in Platts Metals Daily and Metals Week, on fixed pages PMA/MTL412 and 413 and in the Platts price database under the codes listed above.

Please send all comments or questions to aluminum@spglobal.com and pricegroup@spglobal.com.

For written comments, please provide a clear indication if comments are not intended for publication by Platts for public viewing. Platts will consider all comments received and will make comments not marked as confidential available upon request.