Laboratory experimental methods are used to investigate the impacts of supply and/or demand risks on prices, quantities traded, and earnings within forward and spot market institutions. Random demand and/or supply shifts can be as much as 25 percent of the expected equilibrium outcome. Nevertheless, results suggest that the spot or forward trading institution itself has a greater influence on market outcomes than the presence of risk within the trading institution. Sellers tend to have relatively higher earnings in a spot market than buyers, regardless of the risk. Total surplus, however, generally is greater in a forward market.