Spectral Portfolio Theory: From SGD Weight Matrices to Wealth Dynamics

This paper establishes a novel "Spectral Portfolio Theory" that identifies neural network weight matrices trained via stochastic gradient descent as portfolio allocation matrices, demonstrating how their spectral evolution from Marchenko-Pastur to inverse-Wishart statistics unifies diverse wealth dynamics models and yields a Spectral Invariance Theorem with applications in portfolio design, inequality measurement, and tax policy.

Anders G FrøsethWed, 11 Ma💰 q-fin

Dynamically optimal portfolios for monotone mean--variance preferences

This paper provides the first complete characterization of optimal dynamic portfolio choice for monotone mean-variance utility in asset models with independent returns under minimal assumptions, establishing a link between maximal utility and the monotone Sharpe ratio while deriving conditions under which classical mean-variance efficient portfolios remain optimal.

Aleš Černý, Johannes Ruf, Martin SchweizerMon, 09 Ma🔢 math

The Gibbs Posterior and Parametric Portfolio Choice

This paper introduces a generalized Bayesian framework using the Gibbs posterior to derive utility-consistent parametric portfolio policies without modeling the return generating process, and proposes a KNEEDLE algorithm to optimally select the data-weighting parameter in-sample, revealing that characteristic-based gains in U.S. equities (1955–2024) are concentrated pre-2000 and that the optimal weighting depends on risk aversion and higher-order moments.

Christopher G. Lamoureux2026-03-10💰 q-fin

Extensions to the Wealth Tax Neutrality Framework

This paper extends Froeseth's (2026) wealth tax neutrality framework by demonstrating that while neutrality holds under stochastic volatility and Epstein-Zin preferences, it breaks under non-homothetic preferences and four specific implementation channels—such as progressive thresholds and inelastic markets—which are formalized and calibrated to the Norwegian system to evaluate global minimum tax proposals.

Anders G. Froeseth2026-03-06🔬 physics