Price risk for crops arises from changes in market conditions during the crop production period. Prices for both inputs and outputs can change from the time the farmer decides to plant the crop until the time the crop is sold. This statement is true for single season crops as well as perennials and multiseason crops. Shocks to supply of a commodity can arise from many sources, including widespread weather events such as drought or an unusually favorable growing season over a wide area. Shocks to demand can also occur due to a range of factors, including reduced supplies of a competing product such as petroleum with respect to biofuels. Unexpected loss of processing capacity due to damage or financial failure can also shock the demand for an intermediate product such as cellulosic biomass. International trade disruptions and changes in currency exchange rates can affect the prices of many goods and services as well. Crop farmers have experienced very substantial volatility in prices for seed, fertilizer, fuel, and crop products over the past decade.