Portfolio Selection with Multiple Spectral Risk Constraints

TL;DR

This paper introduces an efficient iterative gradient-based algorithm for portfolio selection with multiple spectral risk constraints, significantly outperforming existing solvers in speed and enabling robust risk management.

Contribution

The paper presents a novel, fast algorithm for solving portfolio problems with multiple spectral risk constraints, extending to weighted sums and maxima of spectral measures.

Findings

Algorithm is at least ten times faster than existing solvers.

Efficiently handles multiple spectral risk constraints in portfolio optimization.

Enables robust portfolio design against various risk models.

Abstract

We propose an iterative gradient-based algorithm to efficiently solve the portfolio selection problem with multiple spectral risk constraints. Since the conditional value at risk (CVaR) is a special case of the spectral risk measure, our algorithm solves portfolio selection problems with multiple CVaR constraints. In each step, the algorithm solves very simple separable convex quadratic programs; hence, we show that the spectral risk constrained portfolio selection problem can be solved using the technology developed for solving mean-variance problems. The algorithm extends to the case where the objective is a weighted sum of the mean return and either a weighted combination or the maximum of a set of spectral risk measures. We report numerical results that show that our proposed algorithm is very efficient; it is at least one order of magnitude faster than the state-of-the-art general purpose solver for all practical instances. One can leverage this efficiency to be robust against model risk by including constraints with respect to several different risk models.