LEARN · EN · easyquanttrading.com
What risk actually means in trading
Two traders can both say 'I manage risk' and mean completely different things. One means they size positions so no single trade hurts. The other means they diversify. A third means they have a stop on every order. All three are describing something real, and none of them is describing the others.
- Market risk: how much the position moves against you
- Drawdown risk: the worst peak-to-trough fall you must survive
- Ruin risk: the probability that a losing streak ends the account
- Model risk: the chance your strategy is wrong about the market
- Execution risk: the gap between assumed and realised fills
One: market risk
This is the everyday meaning: the possibility that the instrument moves against your position. It is measured by volatility, and it is controlled by position size and stop placement.
What makes it manageable is that it is symmetric and observable. You can measure how much the instrument typically moves, and you can decide how much of that movement you are prepared to absorb.
Two: drawdown risk
This is the accumulated effect of many market risks arriving in an unfavourable order. It is not the same as market risk, because a strategy with modest per-trade risk can still produce a severe drawdown if its losses cluster.
Drawdown risk is what determines whether you can stay in. The arithmetic is unforgiving: a 25% fall requires a 33% gain to recover, and a 50% fall requires 100%.
Three: ruin risk
Ruin risk is the probability that a sequence of losses reduces your capital to the point where you stop, whether by choice, by margin call, or by having no position size left that is both meaningful and permitted.
| Trades at risk | 10 losses in a row | Cumulative loss |
|---|---|---|
| 1% of equity | Ordinary | about 9.6% |
| 2% of equity | Uncommon but happens | about 18.3% |
| 5% of equity | Painful | about 40.1% |
| 10% of equity | Account-threatening | about 65.1% |
| 20% of equity | Terminal | about 89.3% |
Ten consecutive losses is an entirely normal event for a strategy that wins 45% of the time. The right-hand column ignores compounding to keep it readable.
Four: model risk
This is the risk that your description of the market is wrong — that the edge was fitted, that a look-ahead error slipped in, that costs were understated. It is the risk that cannot be seen in the equity curve, because the equity curve is produced by the same model that contains the error.
Controls for model risk are procedural rather than numerical: hold back data, count your trials, test on a second market, and prefer ideas you can explain. None of them is a measurement, and all of them reduce the chance of being confidently wrong.
Five: execution risk
The difference between the price your logic assumed and the price you actually got. It includes spread widening, slippage, partial fills, and the mundane reality that the bar has closed before your signal exists.
This one is often dismissed as small, and it scales with turnover. A strategy trading several times a day can lose most of its edge to execution without any single fill looking unusual.
Why the distinction matters
Most contradictory advice about risk comes from people talking about different risks with the same words. 'Wider stops reduce risk' is true for ruin risk and false for market risk per trade. 'Diversification reduces risk' is true for drawdown risk and does nothing for model risk if all your strategies share the same flawed assumption.
When someone gives you risk advice, the useful question is which of the five they mean. When you give yourself advice, decide which one you are actually trying to control — and then measure it, because four of the five are measurable and the fifth is the one that ends accounts quietly.
FAQ
- Which risk should I focus on first?
- Ruin risk, because it is the only one that is terminal. Everything else is recoverable given time and capital. Sizing so that a normal losing streak cannot end the account is the first decision, not the last.
- Is volatility the same as risk?
- It is one component. Volatility measures how much price moves; it says nothing about whether your model of the market is correct, or how much you will lose to execution. Treating volatility as the whole of risk is the assumption behind most of the confusion about the Sharpe ratio.
- Can risk be eliminated?
- No. It can be measured, transferred, and sized. A strategy with no risk is a strategy with no position, and any claim to the contrary is either a misunderstanding or a sales pitch.
More guides
- How EasyQuant validates strategies — evidence you can filter
- Honest backtesting, not pretty curves
- Gold strategy research that stays honest
- Overfitting detection: catch it before you deploy
- System Forge: design, then prove
- Walk-forward analysis: the only backtest that fights overfitting
- MT5 export without custody
- Glass box, not black box AI signals
Not investment advice. Historical results do not guarantee future performance. EasyQuant is a research factory — you execute on accounts you control.