Introduction

Abstract

The risk is a phenomenon that appears in almost all economic and financial activities (e.g. in the investment decisions and the operations of financial markets).

According to Diamond and Stiglitz ([20], p.337 ), ” analysis of individual behavior under uncertainty naturally focuses on the meaning and economic consequences of two statements:

1. one situation is riskier than another;

2. one individual is more risk averse than another”.

The construction of mathematical theory of risk has been realized in the framework of probability theory. Probabilistic methods constitute a very efficient tool in the analysis of risk. Moreover they can be succesfully applied only in the case of events which occur with big frequency. The evaluations and forecastings realized with probabilistic risk are efficient when we have a sufficiently large set of data.