Price data methodology

Prices for raw material, precursor, active material, cell, pack, or project service are not directly comparable. A data record should describe specification, quality grade, quantity, delivery location, and added service so readers know what the price covers.

Price can come from public quotation, contract, purchasing record, index, or research, but each has bias and coverage limits. Collection should retain original link or file, acquisition date, sample selection, and cleaning rules, stating what cannot be independently verified.

Across dates, product specification, geography, tax, exchange rate, and market state can change. A time series should record definition changes and missing-data handling, not interpret an old quotation, promotion, or forecast chart as a current executable price.