Speculation is often denounced as "evil," particularly by those who assume that speculative profits derive from luck alone or who are unaware of the overall positive contribution of speculation to market efficiency. Particularly maligned are the profits earned by speculators selling goods that become valuable in the wake of a natural disaster, such as a hurricane. Such profiteers, it is complained, are "cashing in on the misery of others." The obvious implication is that such speculation contributes to the suffering of the victims of the disaster. Leaving aside the ethical question for a moment, how does speculative activity affect the lives of disaster victims in reality?

In such cases speculative profits can only be earned on a consistent basis—that is, providing long-term average gains exceeding the interest rate—insofar as speculators can foresee the likelihood of such adversities and anticipate their effect on market values (). To the extent that they can successfully predict these effects, their speculative activity serves to stimulate an increased production of needed goods in advance of the disaster. In the absence of such activity, the market would be less prepared to satisfy the sudden surge in demand for those goods, rendering them even less plentiful and more costly. In short, the suffering of the victims would in general be increased if speculative activity were absent. Furthermore, because the victims of the disaster trade with the speculators on a voluntary basis (that is, without force, a concept carefully developed in pp. 4.5:8 ff.), each such transaction enables them to realize an improvement on their personal value scales.