Who it is for — Readers who need to measure not only the final return, but also the losses experienced along the way and the time equity took to recover.
A drawdown (DD) is the decline in equity from its previous high. If equity rises to $10,000 and then falls to $8,000, the drawdown from the peak is $2,000, or 20%.
In simple terms — Return compares the start and finish; drawdown looks at the descents along the path. Two strategies with the same ending value may have imposed very different risks and recovery times.
Formal definition
For a positive value curve Vₜ, let 0 start the window and Mₜ = max(Vₛ | 0 ≤ s ≤ t) be its running maximum. A more recent local high below that peak does not replace it. Here magnitudes are nonnegative.
Absolute drawdown: Aₜ = Mₜ − Vₜ
Relative drawdown: Dₜ = (Mₜ − Vₜ) / Mₜ. The percentage value is 100 × Dₜ: 0.20 = 20%. The signed convention in Maximum drawdown is its opposite: DDₜ = −Dₜ.
Drawdown returns to zero when value equals or exceeds the peak. Here underwater duration runs from the last observation at the peak before the decline to the first return to that level or above, unlike peak-to-trough time. An unrecovered episode remains open at the sample end.
To measure performance, neutralise contributions and withdrawals: withdrawing 20 from an otherwise unchanged account of 100 is not a 20% investment loss. An index built from flow-adjusted returns preserves the distinction. Zero or negative value needs separate treatment for ordinary percentages and recovery; a zero peak makes the ratio undefined.
Maximum drawdown
In simple terms — Maximum drawdown is the deepest fall from its own prior peak in the selected window, not the worst loss that could ever occur.
Maximum drawdown (Max DD or MDD) is the largest observed peak-to-trough decline over the analysed period. It therefore depends on the equity path, the start and end of the sample, data frequency, and how deposits, withdrawals and costs are treated.
| Measure | Question answered |
|---|---|
| Current drawdown | How far are we below the latest high? |
| Maximum drawdown | What was the worst peak-to-trough fall in the sample? |
| Time underwater | How long did equity remain below its high? |
| Recovery | How much must equity rise from the trough to regain the peak? |
Limit — Historical Max DD is not a barrier. A short backtest, a new regime, leverage, understated costs or an unseen loss sequence can produce a deeper future drawdown.
Recovery mathematics
In simple terms — Loss and recovery are asymmetric because the recovery begins from a smaller base.
After a drawdown of magnitude x expressed as a fraction with 0 ≤ x < 1 (20% means x = 0.20), the return needed to regain the peak without new contributions is:
Required recovery = x / (1 − x)
The result is also a fraction: 0.25 = 25%. After a 100% loss, no finite percentage return on the zero remaining capital restores the peak. The formula predicts neither the probability nor the time of recovery.
| Drawdown | Recovery required |
|---|---|
| 10% | 11.1% |
| 20% | 25.0% |
| 50% | 100.0% |
Example — A fall from $10,000 to $8,000 is 20%. Recovering $2,000 from an $8,000 base requires a 25% return, not 20%.
Interpreting drawdown without universal thresholds
There is no “normal” drawdown percentage that applies to every strategy. Tolerance depends on the objective, leverage, liquidity, return distribution, horizon, available capital and the ability to follow the plan.
A response to drawdown should be defined in advance:
| Evidence | Control |
|---|---|
| Results remain within tested variability | Check execution, costs and adherence to process |
| Slippage, errors or exposure exceed assumptions | Correct the operational issue and recalculate risk |
| The strategy’s assumptions no longer hold | Apply the predefined suspension or review rule |
| A loss or capital boundary has been crossed | Reduce or stop according to the plan rather than improvising |
Common mistake — Treating past Max DD as a promise, or changing systems, doubling size or skipping signals in an emotional response. Continuing and stopping can both be valid decisions; they should depend on documented criteria and updated evidence.
Summary
- Measure: decline from the previous high, in money or percentage terms.
- Max DD: the worst observation in the chosen window.
- Read alongside: duration, recovery, leverage, liquidity and sample size.
Bronze path — Risk module. Next: R-multiple. Index: Bronze path.
Sources
Malik Magdon-Ismail, Amir Atiya, Amrit Pratap, Yaser S. Abu-Mostafa, On the Maximum Drawdown of a Brownian Motion, Journal of Applied Probability 41(1), 2004, pp. 147–161; PDF — Caltech, pp. 147–149 — absolute peak differences under the Brownian model, not a universal percentage-drawdown formula.
Alexei Chekhlov, Stanislav Uryasev, Michael Zabarankin, Drawdown Measure in Portfolio Optimization, International Journal of Theoretical and Applied Finance 8(1), 2005, pp. 13–58; PDF — Columbia, pp. 19–20, §3.1 — absolute drawdown on uncompounded cumulative returns and related functionals, distinct from the peak-relative percentage used here.
GIPS Standards, Handbook for Firms, 2.A.24 — external-flow adjustment and geometric linking of returns.
Sources accessed 8 September 2026. Examples, percentage conversions and recovery are Cyclepedia teaching calculations, not forecasts.