This research aims to test the random walk hypothesis in Soybean, Cotton, Coffee and Corn markets by using the variance ratio tests. The data used refers to the daily quotations of price indicators, ESALQ/CEPEA for the period from 13/03/2006 to 20/10/2010.Results allowed to conclude that all commodities reject the random walk hypothesis, and hence the efficiency of market, generating arbitrage opportunity.
random walk; variance ratio; commodities
