Stop loss is the core of risk management and should be dynamically set in conjunction with the trading system. Common methods include: ① Fixed ratio method (e.g., -5% forced exit), suitable for volatile markets; ② Trailing stop method (EMA or previous high/low tracking), applicable in trending markets; ③ Volatility anchoring (ATR multiple), can adapt to market rhythm. The key is to avoid emotional interference, and it is recommended to write a trading plan in advance. Statistics show that over 80% of professional traders strictly implement stop loss, but it should be noted that excessively frequent stop losses (<2% position) may exacerbate friction costs. The ideal stop loss should satisfy both risk-reward ratio (≥1:2) and market noise tolerance.