Maximum Adverse Excursion (MAE) Calculator
Find the deepest unrealized loss a trade endured before it closed — the MAE that tells you whether your stop was too tight or too loose.
How it works
MAE per share (long) = max(0, entry − lowest price) · MAE % = MAE per share ÷ entry × 100 · MAE $ = MAE per share × shares
Maximum adverse excursion is the deepest the price moved against you between entry and exit — the worst paper loss the trade ever showed. Logging MAE across many trades reveals where winning trades typically turn around, so you can set a stop wide enough to survive normal noise but tight enough to cut genuine losers. A stop set inside your winners’ typical MAE quietly converts good trades into small losses.
Worked example
You buy 100 shares at $100. The stock sinks to $92 before rallying to a $105 exit. MAE is $8 per share, or $800 (8%), while the realized gain is $500. A stop at $95 would have been hit during that dip and turned a $500 winner into a loss.
Frequently asked questions
What is MAE used for?
It quantifies how much heat a trade took before resolving. By comparing the MAE of your winners and losers, you can place stops beyond the noise your winning trades routinely endure, avoiding stop-outs on trades that would have worked.
How does MAE differ from a drawdown?
Drawdown is a portfolio-level peak-to-trough loss over time. MAE is a single-trade measure: the worst unrealized loss on one position between entry and exit, regardless of where it finally closed.
What is MFE?
Maximum favorable excursion is the mirror image — the best unrealized profit a trade reached before closing. Together MAE and MFE show whether your stops are too tight and your targets too greedy.
Related calculators
Educational estimate, not investment advice. Trading involves risk of loss.