Mads Hebsgaard
Ph.d. Fellow
About
Primary research areas
I develop methods for dependence in financial time series
I study how returns co-move across assets and over time, and how to estimate these links reliably from noisy, high-dimensional financial data. Better models of dependence help investors, pension funds, hedge funds and regulators see where risk is concentrated, how it can spill across sectors and markets, and how to construct portfolios more robustly.
Methodologically, my work focuses on high-dimensional covariance and precision matrix estimation, fragility-adjusted shrinkage, and tests of sector structure in equity portfolios. I use tools from statistics, time-series analysis, resampling and machine learning to build methods that are both theoretically grounded and practically implementable.
I am motivated by problems where technical improvements in estimation can have large ex-post effects, such as more stable portfolios, clearer communication of uncertainty and a more resilient financial system. I particularly enjoy programming, quantitative finance and numerical methods.
Publications
See all publicationsOctober 2025
Fortsat behov for en bedre og simplere ATP-pension
Mads Hebsgaard, Ph.d. Fellow
Henrik Ramlau-Hansen, Associate Professor
Jesper Rangvid, Professor
February 2025
Ny model for ATP-pensionen
Mads Hebsgaard, Ph.d. Fellow
Henrik Ramlau-Hansen, Associate Professor
Jesper Rangvid, Professor
August 2024
Danskernes samlede opsparing
Hvor stor pension er virkelig mulig?
Mads Hebsgaard, Ph.d. Fellow
Henrik Ramlau-Hansen, Associate Professor
Jesper Rangvid, Professor
Recent research projects
Fragility-Adjusted Covariance Shrinkage
Sector Structure in High-Dimensional Portfolios
Links
Selected coding projects: Open-source projects on factor investing, volatility modelling, and a game