Financial institutions rely heavily on Value-at-Risk (VaR) as a risk measure, even though it is not globally subadditive. First, we theoretically show that the VaR portfolio measure is subadditive in the relevant tail region if asset returns are multivariate regularly varying, thus allowing for...

We propose a semi-parametric method for unconditional Value-at-Risk (VaR) evaluation. The largest risks are modelled parametrically, while smaller risks are captured by the non-parametric empirical distribution function. A comparison of methods on a portfolio of stock and option returns reveals...

Point processes induced by stationary symmetric [alpha]-stable (S[alpha]S) processes can have diverse behavior. We distinguish two cases, depending on whether the stationary S[alpha]S process is governed by a dissipative or conservative flow. In the case of dissipative flows, the process is a...

We show that subexponentiality is not sufficient to guarantee that the distribution tail of a sample quantile of an infinitely divisible process is equivalent to the "tail" of the same sample quantile under the corresponding Lévy measure. However, such an equivalence result is shown to hold...

Necessary conditions are given for a symmetric [alpha]-stable (S[alpha]S) process, 1 [alpha] 2, to be Markov. These conditions are then applied to find Markov or weakly Markov processes within certain important classes of S[alpha]S processes: time changed Lévy motion, scale mixed Gaussian...

We study the supremum of 'the' standard isonormal linear process L on a subset of a real Hilbert space H. Upper and lower bounds on the probability that supx[epsilon] LX[lambda], [lambda] large, are found. We treat a number of examples. These include the distribution of the maximum of certain...

We give necessary and sufficient conditions under which a symmetric measurable infinitely divisible process has sample paths in an Orlicz space L[psi] with a function [psi] satisfying the [Delta]2 condition and, as an application, obtain necessary and sufficient conditions for a symmetric...

We obtain the rate of growth of long strange segments and the rate of decay of infinite horizon ruin probabilities for a class of infinite moving average processes with exponentially light tails. The rates are computed explicitly. We show that the rates are very similar to those of an i.i.d....