Another look at the efficiency of markets: the case of the tennis betting exchanges

Abstract

In this article, we investigate the efficiency of the top tennis betting market worldwide using an original database from the Betfair betting exchange. Usually, the results show that the prices have made up a good forecast on the outcome of the matches. Nevertheless, there are evidences that the punters react poorly to the information (which is consistent with the conservatism and anchoring biases) and that they assign a high gain probability to any players who happens to be dominating the match (consistent with the representativeness bias). Several lucrative betting strategies were found, which puts in check the efficiency of the reviewed betting market.