There are websites for each of the crops covered: soya, wheat, coffee and aquaculture (shrimp).

ECONOMIST: Face value

Goldman, then, began trading in commodities, set up a fund and an index (Goldman Sachs Commodity Index) consisting of cattle, coffee, corn, wheat, cocoa, etc.

FORBES: Commodity Bubble Redux In Full Effect

The note consists of futures of contracts of seven agricultural commodities (soybeans, corn, wheat, cotton, soybean oil, coffee and sugar) and tracks the return of the Dow Jones-UBS Agriculture Total Return Sub-Index.

FORBES: Investors Finding Big Gains on Farms