[While the literature usually justifies informational efficiency in the context of rationality, this article shows informational efficiency by applying the evolutionary idea of natural selection. In a dynamic futures market, speculators are assumed to merely act upon their predetermined trading types (buyer or seller), their predetermined fractions of wealth allocated for speculation, and their inherent abilities to predict the spot price, reflected in their distributions of prediction errors with respect to the spot price. This article shows that the proportion of time that the futures price equals the spot price converges to one with probability 1.]

While the literature usually justifies informational efficiency in the context of rationality, this article shows informational efficiency by applying the evolutionary idea of natural selection. In a dynamic futures market, speculators are assumed to merely act upon their predetermined trading types (buyer or seller), their predetermined fractions of wealth allocated for speculation, and their inherent abilities to predict the spot price, reflected in their distributions of prediction errors with respect to the spot price. This article shows that the proportion of time that the futures price equals the spot price converges to one with probability 1.

We perform an asset market experiment in order to investigate whether overconfidence induces trading. We investigate three manifestations of overconfidence: calibration-based overconfidence, the better-than-average effect and illusion of control. Novelly, the measure employed for calibration-based overconfidence is task-specific in that it is designed to influence behavior. We find that calibration-based overconfidence does engender additional trade, though the better-than-average also appears to play a role. This is true both at the level of the individual and also at the level of the market. There is little evidence that gender influences trading activity.