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Strategy #0000000119 · Portfolio optimisation

Minimum-variance portfolio
Enter two volatilities, correlation, long-only constraint, return scenarios and costs.

A minimum-variance portfolio reduces risk using the covariance matrix without forecasting expected returns. Two-asset weights have a closed-form solution; long-only constraints can limit extreme weights and estimation error, but change the solution. Real multi-asset portfolios need robust covariance estimates, constraints and rebalancing costs. This illustration handles two assets only.

Beginner-friendlyAbout 8 minutesEvidence and practical analysis

Three ways in

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

How do two assets’ volatilities and correlation determine minimum-variance weights?

A minimum-variance portfolio reduces risk using the covariance matrix without forecasting expected returns. Two-asset weights have a closed-form solution; long-only constraints can limit extreme weights and estimation error, but change the solution. Real multi-asset portfolios need robust covariance estimates, constraints and rebalancing costs. This illustration handles two assets only.

Enter two volatilities, correlation, long-only constraint, return scenarios and costs.

A two-asset analytical illustration; other portfolio constraints and robust covariance estimation are omitted.

  • Input assumptionsEnter two volatilities, correlation, long-only constraint, return scenarios and costs.
  • Model outputA two-asset analytical illustration; other portfolio constraints and robust covariance estimation are omitted.

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

Variants · same family, different risk levers

Data quality, constraints and implementation costs affect results.

Compare modelling and execution assumptions.

Related strategyRelationshipWhat changesNew cost or risk
Base scenarioManual inputsA minimum-variance portfolio reduces risk using the covariance matrix without forecasting expected returns. Two-asset weights have a closed-form solution; long-only constraints can limit extreme weights and estimation error, but change the solution. Real multi-asset portfolios need robust covariance estimates, constraints and rebalancing costs. This illustration handles two assets only.A two-asset analytical illustration; other portfolio constraints and robust covariance estimation are omitted.
Conservative versionLower exposureRaise cost/risk assumptions and constrain positions.May reduce participation.
Validation versionOut-of-sample testFreeze the method before evaluation on untouched data.Needs more clean data.

A two-asset analytical illustration; other portfolio constraints and robust covariance estimation are omitted.

Read beyond the summary

References

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

  1. 01Jagannathan & Ma (2003), Risk Reduction in Large Portfolios: Why Imposing the Wrong Constraints Helpsresearch