Platts proposes to align weekly and monthly average calculation methodology

Platts, part of S&P Global Commodity Insights, is proposing to update how it calculates weekly and monthly averages to use the closing value from each publishing day during the relevant averaging period, effective June 19, 2023.

This alignment is part of ongoing efforts to ensure consistent methodology application across commodities.

Currently, Platts calculates certain weekly and monthly averages by averaging the high and low values of the published prices separately, and then calculating a midpoint of these resulting values. Instead, Platts would align all averages to calculate the high, low and midpoint averages separately during the averaging period. Platts has calculated that this change would have a negligible impact on resulting values.

The change would affect some published prices across agriculture, chemicals and metals. A list of affected symbols is available here.

For more information about affected averages, please contact pricegroup@spglobal.com.

Please send all comments, feedback and questions to pricegroup@spglobal.com by May 12.

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