Core Definition of Stop-Loss
Stop-loss is a mechanism that automatically sells a stock when its price falls to a preset level. The purpose of this mechanism is to limit the maximum loss per share and protect your capital.
Stop-loss is not a symbol of failure, but a necessary cost of risk control. Just as you buy insurance not because something will definitely go wrong, you set a stop-loss not because you will definitely lose money — it is a preventive measure.
Three Methods of Setting Stop-Loss
Method 1: Pattern Key Level Stop-Loss
Place the stop-loss below the key low of the technical pattern:
| Pattern | Stop-Loss Location | Recommended Distance |
|---|---|---|
| W Bottom | Below the second low | 3-5% |
| Cup and Handle | Below the handle low | 5% |
| VCP | Below the most recent contraction low | 7% |
| Head and Shoulders Top | Above the right shoulder high | 3-5% |
| Flag | Below the flag lowest point | 5-8% |
The advantage of this method is that the stop-loss level has a clear technical basis, not set by feeling.
Method 2: Fixed Percentage Stop-Loss
Set a uniform loss limit for each trade (e.g., 5-8%):
- Short-term trading: Recommended 3-5%
- Medium-term trading: Recommended 5-8%
- Long-term investing: Recommended 8-12%
The advantage of this method is simplicity. The disadvantage is that it does not account for individual stock volatility differences.
Method 3: ATR Dynamic Stop-Loss
Use the ATR indicator to set the stop-loss distance:
- Stop-loss distance = 1.5-2 x ATR
The advantage of this method is that it dynamically adjusts based on each stock actual volatility characteristics, avoiding premature stop-outs on highly volatile stocks.
Psychological Barriers to Stop-Loss
Barrier 1: Unwilling to Accept Loss
Loss triggers loss aversion psychology. Remember: losses are part of trading, no one can be 100% correct.
Barrier 2: Moving the Stop-Loss
Moving the stop-loss further and further away, letting the loss grow larger. Once you set a stop-loss, do not change it arbitrarily.
Barrier 3: No Stop-Loss Habit
Not setting a stop-loss when entering, only regretting after the loss has grown. Stop-loss should be set before entry, not considered afterwards.
Practical Checklist
Confirm before every trade:
- Clear stop-loss price has been set
- Stop-loss distance does not exceed 2% of total capital
- Stop-loss level has a technical basis (not by feeling)
- Confirm you can accept this loss amount
Summary
Three principles of stop-loss:
- Must be set - every trade needs a stop-loss
- Do not change - strictly execute after setting
- Reasonable distance - not too tight (easily triggered by normal fluctuations), not too far (loses protective meaning)
Our quantitative trading strategies all have built-in automatic stop-loss mechanisms, combined with Regime and Risk Analysis to understand current market conditions and develop more precise stop-loss strategies.
For more risk control techniques, see Position Sizing Strategy and Risk-Reward Ratio Guide.