A popular argument states that most of the diversification in a portfolio can be obtained with a rather small number of securities. In this paper we present three algorithms to approach the underlying NP-hard problem of portfolio optimization with a cardinality constraint. All three of these...

Value at risk (VaR) has become a standard measure of portfolio risk over the last decade. It even became one of the corner stones in the Basel II accord about banks' equity requirements. Nevertheless, the practical application of the VaR concept suffers from two problems: how to estimate VaR and...

The convergence of estimators, e.g. maximum likelihood estimators, for increasing sample size is well understood in many cases. However, even when the rate of convergence of the estimator is known, practical application is hampered by the fact, that the estimator cannot always be obtained at...

The great financial turmoil that started 2007 has brought bank regulation back into the political debate. There is talk about imposing new regulations on banks and other financial intermediaries. Yet, we are not convinced that it is completely understood how the existing regulation affects...