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Strategy #0000000080 · Industry structure and equity factors

Industry concentration and competitive structure
Enter the top-three and remaining market shares (total 100%), number of other firms and returns; the remainder is evenly split to approximate HHI.

Industry concentration is often measured by the Herfindahl–Hirschman Index (HHI), the sum of squared market shares. Hou and Robinson study a link between competition and equity returns; concentration may reduce innovation risk while also creating market power and entry barriers. Market definitions, product boundaries and conglomerate treatment change HHI.

Beginner-friendlyAbout 8 minutesEvidence and practical analysis

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Understand the story. Then inspect the risk.

Start with a familiar situation, check the payoff, then test how the numbers change.

The idea · in two minutes

What HHI follows from market shares, and what spread is assumed across concentration groups?

Industry concentration is often measured by the Herfindahl–Hirschman Index (HHI), the sum of squared market shares. Hou and Robinson study a link between competition and equity returns; concentration may reduce innovation risk while also creating market power and entry barriers. Market definitions, product boundaries and conglomerate treatment change HHI.

Enter the top-three and remaining market shares (total 100%), number of other firms and returns; the remainder is evenly split to approximate HHI.

HHI depends on industry boundaries and share estimates; concentration does not causally determine returns.

  • Signal inputEnter the top-three and remaining market shares (total 100%), number of other firms and returns; the remainder is evenly split to approximate HHI.
  • Net scenarioHHI depends on industry boundaries and share estimates; concentration does not causally determine returns.

Illustrative research examples only. They are not live signals or a recommendation.

Variants · same family, different risk levers

Related methods differ in event and signal definitions.

Compare the rule, data and execution assumptions.

Related strategyRelationshipWhat changesNew cost or risk
Core signalEvent / metric ruleIndustry concentration is often measured by the Herfindahl–Hirschman Index (HHI), the sum of squared market shares. Hou and Robinson study a link between competition and equity returns; concentration may reduce innovation risk while also creating market power and entry barriers. Market definitions, product boundaries and conglomerate treatment change HHI.HHI depends on industry boundaries and share estimates; concentration does not causally determine returns.
Conditional sortPortfolio comparisonSort companies on information available at the time.Breakpoints and sample size affect results.
Multi-signal versionFactor combinationCombine another quality or event signal.May add collinearity and multiple-testing risk.

HHI depends on industry boundaries and share estimates; concentration does not causally determine returns.

Read beyond the summary

References

Primary sources and research used to describe the strategy and its limits.

  1. 01Hou & Robinson (2006), Industry Concentration and Average Stock Returnsresearch