excerpt from “The Most Devious Bank Scam Yet” by Matt Taibbi, Rolling Stone, at Reader Supported News, 13 February 14
…The Kochs have been caught up in their own commodity-manipulation schemes, including an episode in 2008, in which they rented out huge tankers and used them to store excess oil offshore essentially as floating warehouses, taking cheap oil out of available supply and thereby helping to drive up energy prices. Additionally, some banks have been accused of similar oil-hoarding schemes.
The motive for the Kochs, or anyone else, to hoard a commodity like oil can be almost beautiful in its simplicity. Basically, a bank or a trading company wants to buy commodities cheap in the present and sell them for a premium as futures. This trade, sometimes called “arbitraging the contango,” works best if the cost of storing your oil or metals or whatever you’re dealing with is negligible – you make more money off the futures trade if you don’t have to pay rent while you wait to deliver….