Commodity exchange prices: The curious case of aluminum
Goldman Sachs Research takes another look at soaring warehouse queues and fears of price distortions in the aluminum market (see previous post here). A case can be made that inventories have risen as consequence of a supply surplus, rather than distortions. The price of physical metal, traded outside the exchange, appears to evolve in line with fundamentals. By contrast, the exchange price trades at a discount, because it only entitles to a warrant for cheapest delivery and not to physical metal at the required location. The variation of this discount constitutes basis risk for producers or consumers that use it for hedging, compromising the validity of the London Metals Exchange prices.