This paper presents a unified treatment of the production and financial decisions available to a firm facing frictionless financial markets and a stochastic production technology under minimal assumptions on the firm's stochastic technology and objective function. The specific focus is on separation results for stochastic technologies, that is, on conditions under which the optimal production decision may be determined without regard to the risk preferences of the firm's owners. Necessary and sufficient conditions for separation, which generalize existing results, are presented. We show, among other results, that separation implies that the linear pricing of assets in the span of the market can be extended to encompass sets of assets outside of the span that are not perfectly replicable.