“My problem with the speculative stories is that they all depend on something that holds production — or at least potential production — off the market. The key point is that the spot price equalizes the demand and supply of a commodity; speculation can drive up the futures price, but the spot price will only follow if the higher futures prices somehow reduce the quantity available for final consumers. The usual channel for this is an increase in inventories, as investors hoard the stuff in expectation of a higher price down the road. If this doesn’t happen — if the spot price doesn’t follow the futures price — then futures will presumably come down, as it turns out that buying futures produces losses.”