Maximum Favorable Excursion
MFE measures the greatest movement in the trade's intended direction after entry and before the chosen exit or evaluation horizon.
For a long trade, it is the greatest favorable rise; for a short trade, it is the greatest favorable decline under the chosen calculation.
Maximum Adverse Excursion
MAE measures the greatest movement against the trade after entry during the same defined observation period.
It helps quantify how much adverse movement successful and unsuccessful trades historically experienced.
Why trade path matters
Two trades can finish with the same return while taking very different paths. One may move directly into profit; another may first experience substantial drawdown.
MFE and MAE retain information that final P&L alone does not show.
Using excursion distributions
Researchers can study MFE and MAE distributions to investigate whether exits, stops or trade-management rules fit observed trade behavior.
The analysis should be performed without using future information that would not have been available at the decision point.
Avoid optimizing to the historical path
Choosing a stop or target solely because it perfectly fits historical excursion data can overfit the sample.
Any rule developed from one dataset should be evaluated on unseen data and with realistic costs.
Historical MFE and MAE distributions do not guarantee future trades will follow the same path.
Key takeaways
- MFE measures maximum favorable movement during a defined trade window.
- MAE measures maximum adverse movement.
- They preserve information about trade path that final return hides.
- Rules derived from excursion analysis require out-of-sample validation.
Sources & further reading
This lesson is educational material. Market structure, exchange rules, fees, margin requirements and derivatives mechanics can differ by venue and can change over time. Verify current rules with the venue you use.