We show that in the delta-normal model there exist perturbations of the Gaussian multivariate distribution of the returns of a portfolio such that the initial marginal distributions of the returns are statistically undistinguishable from the perturbed ones and such that the perturbed V@R is close to the worst possible V@R which, under some reasonable assumptions, is the sum of the V@Rs of each of the portfolio assets.
@article{bwmeta1.element.bwnjournal-article-doi-10_7151_dmps_1148, author = {Manuel L. Esqu\'\i vel and Lu\'\i s Dimas and Jo\~ao Tiago Mexia and Philippe Didier}, title = {Small perturbations with large effects on value-at-risk}, journal = {Discussiones Mathematicae Probability and Statistics}, volume = {33}, year = {2013}, pages = {151-169}, zbl = {1315.60021}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_7151_dmps_1148} }
Manuel L. Esquível; Luís Dimas; João Tiago Mexia; Philippe Didier. Small perturbations with large effects on value-at-risk. Discussiones Mathematicae Probability and Statistics, Tome 33 (2013) pp. 151-169. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_7151_dmps_1148/
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