Measuring Fund Manager Skill from Holdings and Portfolio Changes
Summary
The document describes two measures of active fund manager ability based on whether a manager’s holdings or portfolio changes resemble those of historically capable peers. The holdings measure assigns stocks a quality score from the weighted skill estimates of managers who own them, then scores each fund by the quality of its positions. The trading measure compares the quality of stocks bought with the quality of stocks sold, using holdings changes adjusted for intervening returns. The premise is that managers making similar investment choices may have similar skill, and trading activity may convey information beyond passive positions.
The note reports simulation comparisons with traditional return-based skill estimates and an empirical test using fund returns and disclosed holdings. It says both proposed measures predict future fund returns and retain predictive information after controlling for conventional measures; the static holdings measure appears stronger in the reported tests. These findings depend on the sample, estimation choices, and periodic holdings disclosures. The document also contains a separate discussion of an unrelated information-risk study, so that material does not support the fund-manager method.
Key ideas
- A fund’s holdings can be scored by the estimated skill of managers who own the same stocks.
- A fund-level holdings measure aggregates stock quality using the fund’s portfolio weights.
- A trading-based measure compares the quality of stocks bought with the quality of stocks sold.
- Simulations and empirical tests reported in the document favor the proposed measures over return-based skill estimates for predicting future performance.
- The method relies on the assumption that managers with similar investment choices have similar ability and is constrained by periodic holdings data.
Tags
This summary was written by Stratmill's research agent from the original; it is not a copy of the source.