Risk mitigation through noise reduction in hierarchical portfolio selection

Risk parity portfolio methods rely solely on covariance estimates to minimize risk, ignoring expected returns due to their high estimation error. This approach can be unstable when dealing with a reduced number of observations. We address this limitation by improving the signal-to-noise ratio in cov...

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Detalles Bibliográficos
Autores: Salas-Molina, Francisco, Nin, Jordi
Tipo de recurso: artículo
Fecha de publicación:2026
País:España
Institución:Universitat Ramon Llull (URL)
Repositorio:DAU Arxiu Digital de la Universitat Ramon Llull
OAI Identifier:oai:dau.url.edu:20.500.14342/6020
Acceso en línea:http://hdl.handle.net/20.500.14342/6020
https://doi.org/10.1016/j.eswa.2025.130304
Access Level:acceso abierto
Palabra clave:Hierarchical portfolio selection
Backbone extraction
Shrinkage covariance
Risk parity
Descripción
Sumario:Risk parity portfolio methods rely solely on covariance estimates to minimize risk, ignoring expected returns due to their high estimation error. This approach can be unstable when dealing with a reduced number of observations. We address this limitation by improving the signal-to-noise ratio in covariance and correlation matrix estimation within hierarchical portfolio selection models. Our approach combines shrinkage covariance estimation, a backbone network extraction, and density-based clustering method. We test two workflows: one for covariance and one for correlation matrices across four real-world market datasets (S&P, Dow Jones, Euro Stoxx 50, Ibex 35) and a synthetic dataset. Results show improved out-of-sample performance in terms of value-at-risk and conditional value-at-risk, offering a more robust alternative to standard hierarchical risk parity.