Measuring Leakage in Rank-Dependent Portfolio Strategies

Summary

This paper studies leakage in trading strategies generated from rank-dependent portfolio functions. Leakage refers to wealth lost when the stocks included in a portfolio are renewed or replaced. The authors derive a theoretical expression for this effect as a finite-variation term and state that their calculation differs from methods proposed in earlier research. They then introduce a discrete-time estimation method and discuss practical considerations for applying it.

An empirical example illustrates leakage for strategies using constituent lists of different sizes. This makes constituent turnover a relevant consideration when evaluating portfolios built from changing stock ranks: performance analysis may need to account for the effect of replacing holdings. The document does not report the magnitude of leakage, identify specific market periods, or establish whether the strategies remain profitable after accounting for it. Its contribution is a framework for defining and estimating the effect, rather than evidence that a particular portfolio rule will outperform.

Key ideas

• Leakage is defined as wealth loss associated with renewing a strategy’s constituent stocks.
• For rank-dependent functionally generated strategies, the theoretical leakage is expressed as a finite-variation term.
• The paper presents a discrete-time method for estimating leakage and notes practical considerations.
• An example compares leakage across different constituent list sizes.
• The document does not provide enough reported results to assess net profitability after leakage.

Tags

# Leakage of rank-dependent functionally generated trading strategies


# Leakage of rank-dependent functionally generated trading strategies









This paper investigates the so-called leakage effect of trading strategies generated functionally from rank-dependent portfolio generating functions. This effect measures the loss in wealth of trading strategies due to renewing the portfolio constituent stocks. Theoretically, the leakage effect of a trading strategy is expressed explicitly by a finite-variation term. The computation of the leakage is different from what previous research has suggested. The method to estimate leakage in discrete time is then introduced with some practical considerations. An empirical example illustrates the leakage of the corresponding trading strategies under different constituent list sizes.

Shown in full with attribution under the source's licence. Licence: abstract CC0

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.