Stock returns and their probabilistic distribution (the Bucharest Stock Exchange case)

Based on a long series of papers analyzing stock returns behavior we can speak generally about the stock exchange as a speculative market in the sense of the stable paretian hypothesis. Still, there are significant differences from a market to another and in many cases biases from normality are too insignificant in order to justify a radical change of approach. This radical change is less needed especially when the aggregating interval of price changes gets big enough, for example if we speak about weakly or monthly returns, cases in which the non normality hypothesis can be accepted in a comfortable way.