Cathode

Cathode is refined metal, most often copper, cast into flat sheets of high purity that meet an exchange's delivery standard and can be sold directly into manufacturing.

Cathode is the finished, high-purity form that refined copper takes when it is cast into flat sheets ready for sale, the last step after ore is mined, concentrated, smelted, and electrolytically refined. Its purity meets the standard set by commodity exchanges, which is what makes it eligible for delivery against a futures contract and acceptable to manufacturers without further processing.

Cathode is the form in which most refined copper actually changes hands in international trade, distinct from the concentrate that mines without their own smelters ship instead. Exchange-approved cathode held in exchange warehouses counts as certified stocks, one of the most closely watched inventory measures in the copper market, since it shows how much immediately deliverable metal is available.