To explore why bubbles frequently emerge in the experimental asset market model of Smith et al. (1988, henceforth SSW), we vary the fundamental value process (constant or decreasing) and the cash-to-assetvalue-ratio (constant or increasing). We find that a declining fundamental value is the main driver for mispricing and overvaluation. A questionnaire reveals that most subjects do not understand the declining fundamental value process in SSW, but expect the fundamental value to stay constant or increase. Running the experiment with a different context (“stocks of a depletable gold mine” instead of “stocks”) significantly reduces mispricing and overvaluation, which highlights the sensitivity of the SSW model to the context in which it is presented.