[betaclass]

You BUY PUT options -- you buy the right to sale at a given price for some period of time. The most you can lose is what you paid out for the put option. If the price of the underlying commodity falls below the strike price, you essentially get the difference -- you buy at the new lower price and sell at the higher price.

[jessriedel]

Ahh I've of course heard of these. Thanks. This sounds like something Coinsetter would do. The only problem is that it puts the seller of the put option on the hook for an uncapped loss. Presumably there is some way to combine these techniques to allow downward pressure on a stock/index while making sure no one has to be so exposed.