Working in a complete-markets setting, a property of asset demands in identified that is inconsistent with the investor's preference being based on probabilities. In this way, a market counterpart of the Ellsberg Paradox is provided.

Evidence such as the Ellsberg Paradox shows that decision-makers do not assign probabilities to all events. It is intuitive that they may differ not only in the probabilities assigned to given events but also in the identity of the events to which they assign probabilities. This paper describes...