Fastmarkets extends consultation on Asia-Pacific copper concentrates TC/RC index, proposes gold and silver normalization

The proposal was first published on April 8. The proposal was preceded by an open consultation on the copper concentrated index weighting and gold and silver normalization published on February 3, 2026.

The feedback period has been extended to July 31 with a revised proposed implementation date of September 4, 2026.

Fastmarkets proposes to introduce a dynamic volume weighting of trader and smelter purchases in the final index calculation, adjusted weekly based on reported price and volume data over a rolling six-month period.

The extension of this dynamic weighting allows for additional public comment. The following indices are affected:

• MB-CU-0287 Copper concentrates TC index, cif Asia Pacific, $/tonne
• MB-CU-0288 Copper concentrates RC index, cif Asia Pacific, US cents/lb

Currently, Fastmarkets applies a fixed 50:50 weighting for the calculation of the two indices listed above.

Fastmarkets also proposes to normalize gold and silver content and payables within the index calculation to base specifications. Where gold or silver content is below the payable threshold, the reported treatment and refining charges (TC/RCs) may reflect a credit or deduction relative to material at the base specification.

As part of the normalization, Fastmarkets will normalize the reported gold and silver content, the applicable deduction or payable threshold, the payable percentage, the prevailing precious metal price on the day of the reported transaction, and standard unit conversions used in the market.

As part of this, Fastmarkets also proposes to change the gold (Au) base specification from 1.1g per dmt to 1.0g per dmt, and the silver (Ag) base specification from 75g per dmt to 30g per dmt. The maximum specifications for gold and silver would remain unchanged at 30g per dmt and 350g per dmt respectively.

This change came from sustained, unprecedented tightness since late 2023 in the copper concentrates market, fierce competition and the surge in gold and silver prices. 

The following indices are affected:

• MB-CU-0287 Copper concentrates TC index, cif Asia Pacific, $/tonne
• MB-CU-0288 Copper concentrates RC index, cif Asia Pacific, US cents/lb
• MB-CU-0508 Copper concentrates TC implied smelters purchase, cif Asia Pacific, $/tonne
• MB-CU-0510 Copper concentrates RC implied smelters purchase, cif Asia Pacific, cents/lb
• MB-CU-0509 Copper concentrates TC implied traders purchase, cif Asia Pacific, $/tonne
• MB-CU-0511 Copper concentrates RC implied traders purchase, cif Asia Pacific, cents/lb

Please send any questions or comments by July 31 to pricing@fastmarkets.com and basemetals@fastmarkets.com. Please add the subject heading “Re: Copper Concentrates TC/RC Index.” Please indicate if comments are confidential. Fastmarkets will consider all comments received and will make comments not marked as confidential available upon request.

To see all Fastmarkets pricing methodology and specification documents, go to the Fastmarkets methodology page.