Drawdown and maximum loss
Lesson 22 · practical guide
Drawdown is the decline from a previous peak in balance or equity. It matters because recovery requires a larger percentage gain than the original loss and because rules may force a close.
What you will learn
Measure drawdown so you know how much recovery a loss requires.
Key terms
- Peak-to-trough drawdown — the percentage fall from a high to a later low.
- Recovery factor — the gain needed to return to the previous peak.
- Maximum loss rule — a limit that stops risk from compounding after a bad run.
Follow these steps
- Record the highest account value before each decline.
- Calculate drawdown as (peak minus current value) divided by peak.
- Translate the loss into the gain required to recover; a 50% loss requires 100%.
- Set a hard stop for the day, trade or account and honour it when emotions are strongest.
Practical advice
A drawdown is not just an uncomfortable percentage; it changes the mathematics of recovery and the psychology of decision-making. Protecting capital keeps future choices available.
Long-form explainer
The full guide
Read this lesson as a chapter: understand the mechanism, test the assumptions and apply the idea with a clear risk limit.
Drawdown measures the path, not only the final result
Peak-to-trough drawdown measures the fall from a previous high to a later low. It tells you what an investor had to endure before a recovery, which a final return can hide. A portfolio that ends higher may still have experienced a loss large enough to cause forced selling or a change in life plans.
Recovery is asymmetric. After a 20% loss, the remaining capital needs a 25% gain to return to its starting point. Larger losses require disproportionately larger gains. This is why maximum-loss rules and position limits are more important than celebrating a single winning period.
Turn drawdown into a decision rule
Set a review threshold before the loss occurs. At that point, pause new risk, check whether the thesis or circumstances changed and reduce exposure if the original risk budget no longer fits. Do not automatically double a position because the price is lower; a lower price can reflect a permanently weaker asset.
Track drawdown at the portfolio level and by position. Include deposits and withdrawals consistently, and distinguish market loss from cash-flow changes. A simple record of peak value, trough value, recovery and cause creates a useful feedback loop without pretending that risk can be measured perfectly.
What usually goes wrong
The mistake that matters most is thinking of a drawdown as an uncomfortable percentage rather than as a change in the mathematics. Recovery is not symmetrical: the deeper the fall, the more disproportionate the gain required to get back. That is why limiting the worst outcome does more for a long-term result than improving the average one. The second error is measuring drawdown only on closed trades, which hides how bad things looked while positions were open and is precisely the number that determines whether someone panics.
People also assume the worst drawdown they have experienced is the worst possible. It is simply the worst so far, usually in a short sample, and a strategy tested only in favourable conditions has not been tested. The final failure is having no predefined response. Without a rule that reduces size or stops trading at a defined level, the decision is made under stress, after losses, when judgement is at its worst. Write the threshold and the action now, while nothing is going wrong and the number is still abstract.
How it works
A 10% loss needs an 11.1% gain to recover; a 50% loss needs 100%. Track realised and unrealised losses because programmes may use equity, not only closed trades.
Limits may be static, daily, total or trailing and may use a high-water mark. A profitable strategy can still breach a rule because of its path.
Worked example
Numbers make an idea concrete. Here is a small, illustrative one — not a forecast.
€10,000 falling to €8,000 is a 20% drawdown. Returning to €10,000 requires a 25% gain from €8,000.
Before you act
Run through these questions before you commit any money or make a decision based on this lesson:
- Which peak and value are compared?
- Is the limit balance, equity or trailing?
- What size stays below normal loss?
- When do I stop trading?
Practice this lesson
Reading is a start; doing the exercise is what makes the idea stick.
Make a table for 5%, 10%, 20% and 40% losses, adding the recovery percentage and a behaviour rule for each level.
Further reading
Educational content only: This guide is not personal financial, legal or tax advice. Markets involve risk, including the possible loss of capital. Verify current rules, fees and product availability in your country.