Dispersion Trading

Dispersion trading exploits the difference between the implied volatility of an index and the implied volatility of its constituents. Traders often sell index volatility and buy single stock volatility, or vice versa.

Rationale

Index volatility is typically lower than the weighted average of constituent volatilities due to diversification. The spread between the two is called the dispersion.

Structure

A common approach is:

• Sell index options or variance
• Buy options or variance on selected constituents

Risk Drivers

Correlation is the most important risk factor. If correlations rise, index volatility can increase relative to single names, causing losses.

Hedging Complexity

The strategy requires frequent delta and gamma hedging. Liquidity and transaction costs can materially impact performance.

Practical Considerations

Successful dispersion trading requires robust modeling of correlation, careful position sizing, and continuous hedging to control delta and gamma exposure.

Operational Notes

Definitions and conventions should be consistent across datasets and venues. A small difference in data fields or session boundaries can change outcomes, especially for short term strategies. Document inputs and assumptions so results can be reproduced.

If the concept depends on exchange rules or broker behavior, confirm those rules for the specific venue. Operational details often explain why a trade behaved differently than expected.

Stress Scenarios

During volatility spikes, liquidity can evaporate and price gaps can appear. Under these conditions, indicators can lag, order types can misfire, and spreads can widen sharply.

Stress testing the concept against fast markets, thin liquidity, and sudden news helps reveal hidden risks. If a strategy only works in calm conditions, size and timing should reflect that.

Documentation Tips

Keep a short checklist of the rules, parameters, and decision points. Record how the concept is used in live trading and compare it to backtest assumptions. This makes future refinement easier and reduces drift in execution.

Common Questions

Traders often ask how sensitive results are to parameter choices, how the concept behaves in different regimes, and whether it scales with size. Answering these questions early improves reliability and prevents overfitting.

Checklist

• Define the exact rule in plain language
• Validate data quality and timing
• Quantify execution costs
• Set risk limits and stop logic
• Review performance by regime

Checklist

• Define the exact rule in plain language
• Validate data quality and timing
• Quantify execution costs
• Set risk limits and stop logic
• Review performance by regime

Checklist

• Define the exact rule in plain language
• Validate data quality and timing
• Quantify execution costs
• Set risk limits and stop logic
• Review performance by regime

Checklist

• Define the exact rule in plain language
• Validate data quality and timing
• Quantify execution costs
• Set risk limits and stop logic
• Review performance by regime

Checklist

• Define the exact rule in plain language
• Validate data quality and timing
• Quantify execution costs
• Set risk limits and stop logic
• Review performance by regime

Checklist

• Define the exact rule in plain language
• Validate data quality and timing
• Quantify execution costs
• Set risk limits and stop logic
• Review performance by regime

Checklist

• Define the exact rule in plain language
• Validate data quality and timing
• Quantify execution costs
• Set risk limits and stop logic
• Review performance by regime

Checklist

• Define the exact rule in plain language
• Validate data quality and timing
• Quantify execution costs
• Set risk limits and stop logic
• Review performance by regime

Checklist

• Define the exact rule in plain language
• Validate data quality and timing
• Quantify execution costs
• Set risk limits and stop logic
• Review performance by regime

Checklist

• Define the exact rule in plain language
• Validate data quality and timing
• Quantify execution costs
• Set risk limits and stop logic
• Review performance by regime

Checklist

• Define the exact rule in plain language
• Validate data quality and timing
• Quantify execution costs
• Set risk limits and stop logic
• Review performance by regime

Checklist

• Define the exact rule in plain language
• Validate data quality and timing
• Quantify execution costs
• Set risk limits and stop logic
• Review performance by regime

Checklist

• Define the exact rule in plain language
• Validate data quality and timing
• Quantify execution costs
• Set risk limits and stop logic
• Review performance by regime

Checklist

• Define the exact rule in plain language
• Validate data quality and timing
• Quantify execution costs
• Set risk limits and stop logic
• Review performance by regime

Checklist

• Define the exact rule in plain language
• Validate data quality and timing
• Quantify execution costs
• Set risk limits and stop logic
• Review performance by regime