Every structure has natural frequencies. Minor shocks in these frequencies can bring down any structure, e.g. a bridge. An Investment Universe also has natural frequencies, characterized by its eigenvectors. A concentration of risks in the direction of any such eigenvector exposes a portfolio to...

We evaluate the impact of extreme market shifts on equity portfolios and study the difference in negative and positive reactions to market jumps with implications for portfolio risk management. Employing high-frequency data for the constituents of the S&P500 index over the period 2 January 2003...

The 2015 Paris Agreement is a landmark in limiting emissions and targeting global warming well below 2, preferably 1.5, degrees Celsius compared to pre-industrial levels. In this light, we investigate how to efficiently construct equity portfolios that help mitigating climate change risk but at...

Risk parity has been considered a heuristic asset allocation method. In this paper, we show that, to the contrary, risk parity is a special case of a mean-risk type of a portfolio optimization problem with log-regularization to constrain weights. We show that log-regularization leads to a fund...

We present an analytical framework for active strategic risk management for sovereign wealth funds (SWFs). This paper extends our previous work on foreign exchange reserves management that integrates risk-return objectives with macroeconomic, macro-prudential and sovereign debt management...

Time horizon dimensions are added to asset pricing theory. Single period, static, arbitrage pricing theory (APT) describes single period risk with long horizon contributions in the frequency domain. Mean-reversion risks correspond to horizon variances. Mean-reversion risk is measured using the...

This paper presents the results of an empirical study concerning conventional and socially responsible mutual funds.We apply a sophisticated operations research algorithm embedded in inverse portfolio optimization on financial market data, ESG-scores and CRSP fund data. Due to our results we...

This study develops and implements a theory and method for analyzing whether introducing new securities or relaxing investment constraints improves the investment opportunity set for risk averse investors. We develop a test procedure for ‘stochastic spanning’ for two nested polyhedral...

This article investigates the sensitivity analysis of mean-variance portfolio holdings to changes in the upper bounds. The optimization problem studied in this paper is, thus, constrained by a restriction that no more than certain portion of wealth can be invested in any one security. Our...

I develop a stochastic growth model with production where there is a hidden state governing productivity growth regimes, and the hidden state evolves according to a Markov chain. Economic agents learn about the hidden state and display ambiguity aversion in the spirit of Klibanoff et al. (2005)....