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Are Three Matrices All You Need To Beat the Market? Observable Matrix Dynamics for Portfolio Optimization

Portfolio Management 2026-07-29 v1 Risk Management Statistical Finance

Abstract

We present a simple framework for dynamic portfolio management that uses nothing but daily prices, trading volumes, and market capitalizations. Its state is three fixed-size matrices built from the price history: the distance matrix of the return correlations and the transition matrices of two Markov chains that rank the S\&P 500 names monthly by trailing return and by trailing volatility. These three matrices rest on the price history alone, the same information Markowitz mean-variance optimization draws on, but they replace its expected-return vector and covariance matrix. Our method requires no matrix inversion, works on outlier-robust cross-sectional ranks, and is dynamic rather than single-period. Empirically the volatility rank is forecastable one step ahead while the return rank stays close to unforecastable. A portfolio built on the forecasts, a market-neutral momentum long-short blended with an opportunistic long-only sleeve, beats the market on two non-overlapping out-of-sample test sets, January 2022 to December 2024 and January 2025 to July 2026, at Sharpes of 1.061.06 and 1.321.32 against the market's 0.780.78 and 1.141.14, respectively, net of a five-basis-point trading cost and marked to market daily. It also outperforms the classical minimum-variance and maximum-diversification portfolios. Diversifying the long sleeve by residual distance adds a further edge on both periods, lifting the Sharpe to 1.081.08 and 1.441.44 and the annualized return from 18%18\% to 20%20\% and from 44%44\% to 56%56\%, respectively. A convex information-leader overlay separately insures the market-neutral sleeve, buying convexity and a shallower drawdown at a small cost in return, the Sharpe unchanged.

Keywords

Cite

@article{arxiv.2607.27461,
  title  = {Are Three Matrices All You Need To Beat the Market? Observable Matrix Dynamics for Portfolio Optimization},
  author = {Igor Halperin},
  journal= {arXiv preprint arXiv:2607.27461},
  year   = {2026}
}

Comments

50 pages, 21 figure