Drawdown

What it is

Drawdown is the peak-to-trough decline in account equity over a measured period. If an account climbs to $50,000, falls to $45,000, then recovers and climbs to $55,000, the drawdown over that interval was $5,000 — measured from the prior equity peak to the lowest point reached before a new peak was made. Drawdown can be expressed in dollars, in percentage of starting account, in percentage of peak equity, or normalized in R-multiples of the strategy's per-trade risk.

Maximum drawdown — the largest peak-to-trough decline over the full sample — is the single most important risk statistic for any trading system or account. It quantifies the worst pain experienced and sets a lower bound on the capital needed to survive that pain without forced liquidation or psychological capitulation.

Why it matters

Drawdown determines whether a trader survives long enough to realize a strategy's edge. A system with a great expected return but a 60% maximum drawdown is functionally unusable for most accounts — either the position size must be cut so aggressively that the dollar returns become trivial, or the trader will quit during the drawdown before recovery. Sizing every strategy around its historical drawdown, padded for the fact that future drawdown is almost always worse than past drawdown, is the standard risk-management posture.

Practical uses include:

• Setting maximum acceptable position size based on the strategy's worst historical drawdown.
• Triggering risk-off rules (cut size, pause trading, review setups) when current drawdown approaches a defined threshold.
• Comparing strategies on a risk-adjusted basis — return per unit of drawdown, not just raw return.

How it appears on Sierra Chart

Sierra Chart's built-in trade simulation and replay tools track equity curves and report drawdown statistics for simulated runs. For live trading, the SCS Trading Journal computes drawdown across the trader's actual order history, plotting equity curves and reporting maximum drawdown alongside other performance metrics.

Per-trade drawdown — MAE, or Maximum Adverse Excursion — is the trade-level cousin of account drawdown, measuring the worst unrealized loss inside a single trade rather than across the account.

Common patterns / pitfalls

• Past drawdown is a lower bound on future drawdown, not an upper bound. Markets always have a way to produce a worse drawdown than the backtest showed.
• Drawdown depth and drawdown duration are different things. A 20% drawdown that recovers in two weeks is far easier to live with than a 20% drawdown that takes six months to climb out of.
• Position sizing changes drawdown linearly — halving size halves drawdown. This is the simplest lever for risk control.
• Drawdown in dollars and drawdown in percent diverge as the account grows. Track both.

Related SCS studies

The SCS Trading Journal is the natural surface for drawdown tracking on live accounts — it ingests order history, computes equity curves, and reports drawdown alongside Sharpe, profit factor, and per-trade R-multiples.