Portfolio insurance strategies based on options typically treat the investment in the risky asset, e.g., stock, as fixed. We show in a mean/downside-risk framework that such a strategy is inefficient. Using at the money put options, expected returns can be increased by more than 250 basis points...

This paper provides an extensive Monte-Carlo comparison of several contemporary cointegration tests. Apart from the familiar Gaussian based tests of Johansen, we also consider tests based on non-Gaussian quasi-likelihoods. Moreover, we compare the performance of these parametric tests with tests...

Market efficiency tests that rely on the martingale difference be-havior of returns can be based on various volatility measures. This paper argues that, to be able to differentiate between dependence and fat-tailedness. one should look simultaneously at plots based on ab-solute returns and...

We derive the exact loss distribution for portfolios of bonds or cor-porate loans when the number of risks grows indefinitely. We show that in many cases this distribution lies in the maximal domain of attraction of the Weibull (Type III) limit law. Knowledge of the dis-tribution and its tail...

Many financial time-series show leptokurtic behavior, i.e., fat tails. Such tail behavior is important for risk management. In this paper I focus on the calculation of Value-at-Risk (VaR) as a downside-risk measure for optimal asset portfolios. Using a framework centered around the Student t...

This article focuses on the relevance of long-term equilibrium relations for financial decision making. Special attention is devoted to optimal asset allocation in the presence of possibly cointegrated time-series, e.g., asset prices. Using a stylized asset allocation problem, the link is...

This paper considers a semi-nonparametric cointegration test. The test uses the LM-testing principle. The score function needed for the LM-test is estimated from the data using an expansion of the density around a Student t distribution. In this way, we capture both the possible fat-tailedness...

Internal risk management models and downside-risk measures such as Value-at-Risk (VaR) play an important role in contemporary banking practice. VaR measures the maximum loss born by a bank or other financial institution over a certain time period and given a certain level of confidence....

We consider portfolio credit loss distributions based on a factor model for individual exposures and establish an analytic characterization of the credit loss distribution if the number of exposures tends to infinity. Using this limiting distribution, we explain how skewness and leptokurtosis of...