In the late 90s an increasing interest has been developing towards risk measures, in particular the Value at Risk (VaR) and the Conditional Value at Risk (CVaR). The use of such risk measures is due, on the one hand, to the rules imposed by the Basel Accord on the deposit of margins by banks and financial institutions because of the financial risks they are exposed to. On the other hand, these tools are important to quantify the riskiness assumed by an investor or an intermediary because of his financial transactions.