2. Risk measures used in the finance and insurance
2.1. Value-at-Risk
In the class of quantile-based risk measures, the most used is Value-at-Risk, which evaluates the maximal loss
that can occur in a time horizon with a given probability level.
Let X : Ω → R a random variable defined on the
probability space (Ω, K, P), with cumulative distribution function
Let D (0, 1). The Value-at-Risk corresponding to a random variable X at the probability level D is given by:
If the random variable X has a continuous one-to-one cumulative distribution function, then VaRα(X) can be computed as the unique solution of the equation:
Value-at-Risk is used for setting the capital adequacy limits for banks and other financial institutions and plays an
important role in investment, risk management and regulatory control of financial institutions.