“Prediction market” has always been a strange name to me, since prices in all kinds of markets are predictions. The price of a company’s stock is a reflection of an aggregate prediction about the net present value of its future cash flows, the price of an option comes from a prediction about the paths some underlying asset’s price might take, and so on. Further, if the strongest form of EMH is true, all knowable future event probabilities are already reflected in market prices.