Copper Concentrates Pricing Overhaul: Fastmarkets Shifts to Dynamic Weighting

The way copper concentrates are priced has been revamped by Fastmarkets with its dynamic weighting framework. This new system replaces a static 50:50 model, which assumed that traders and smelters participate equally in the spot market.

Under the old methodology, the combined TC/RC index was calculated as an average of two sub-indices, each carrying exactly 50% weight regardless of their actual market participation. However, this approach has become outdated due to uneven distribution of spot market activity between traders and smelters.

The new dynamic weighting model adjusts weekly based on the proportion of reported physical transaction volumes attributable to each counterparty type. Only formally reported transactions are eligible for inclusion, creating a direct incentive for greater transparency. The use of a rolling six-month window ensures that short-term volume spikes do not cause erratic swings in the combined index weight.