“…In the present work, among many approaches existing in the literature to estimate the parameters of a SDE (see, for instance, Poletti Laurini & Hotta, , and references therein), we applied the estimating function approach for ergodic diffusion models introduced in Bibby, Jacobsen, and Sørensen (), which turned out to be very useful in obtaining optimal estimators for the parameters of discretely sampled ergodic Markov processes, whose likelihood function is usually not explicitly known. In Orlando et al () a better performance of the latter method is shown by comparing its efficiency with the maximum likelihood estimation routine implemented in MATLAB for the CIR process by Kladívko (). In (Bibby et al, ), example 5.4 the authors constructed an approximately optimal estimating function for the CIR model, from which they derived the following explicit estimators of the three parameters based on a sample of observed market spot rates : …”