Before revision:  However, it has been shown on one example, the Euro future contract, that the difference between real financial time series and random walks, as small as it is, is detectable using modern statistical multivariate analysis .
After revision:  At first approximation the difference between real price changes and the random walk model is too small to be detected using traditional time series analysis. However, we show in the following that this difference between real financial time series and random walks, as small as it is, is detectable using modern statistical multivariate analysis .