Every commodity trader is told the LME warrant is as good as gold: title to metal, freely transferable, liquid paper. For one period in the early 2010s, the aluminum market put that claim through a stress test the industry still studies. Owners of LME aluminum discovered that holding a warrant to metal in a Detroit warehouse meant waiting over a year to physically touch it, while paying rent on every intervening day, and that the party collecting the rent often had commercial

A copper offer can mean two very different things depending on one word most sellers gloss over: concentrate or cathode. One is a semi-processed ore product that still needs a smelter and a refinery before it's usable. The other is finished, LME-deliverable metal. Confusing the two, or letting a seller blur the distinction, is where a lot of copper deals go wrong before price is even discussed. This piece breaks down how copper actually moves from ore to refined metal, where