为什么止损也能让账户破产？

Core Viewpoint - The article discusses the controversial topic of "stop-loss" strategies in investing, highlighting a recent paper by Nassim Nicholas Taleb that quantifies the effects of stop-loss through Monte Carlo simulations, suggesting that stop-loss may lead to more losses rather than preventing them [1][2]. Summary by Sections Stop-Loss Strategy Analysis - The paper presents a key graph showing the distribution of returns with and without stop-loss, indicating that while stop-loss can reduce the probability of large losses, it also creates a peak of losses at the stop-loss threshold, termed "Dirac Mass" [5][6]. - In a market with a volatility of 20-25%, a fixed 10% stop-loss has a 50% chance of being triggered, which is higher than many investors expect [5][6]. - For A-shares, particularly in small-cap and tech stocks, the annualized volatility can reach 60%, resulting in an 85% chance of triggering a 10% stop-loss [6]. Recommendations for Stop-Loss - The paper suggests that a fixed stop-loss below 20% is ineffective against random noise and should be reconsidered [6]. - Stop-loss levels should be adjusted based on market volatility; in low-volatility markets, a 10% stop-loss may only trigger 15% of the time, making it a viable strategy [6]. - Fixed percentage stop-losses are not ideal; investors should consider their investment strategy and fundamentals to set stop-loss levels that are unlikely to be triggered under normal conditions [7]. Practical Issues with Stop-Loss - The article identifies three main issues that can exacerbate the negative impact of stop-loss on accounts: 1. Poor opportunity selection can lead to unnecessary stop-loss triggers, as illustrated by the trading experiences of Jesse Livermore [11]. 2. Trading in a non-trending, volatile market can result in frequent stop-loss triggers, leading to cumulative losses [12]. 3. High leverage increases the risk of permanent losses, making stop-loss more critical but also amplifying its negative effects [13]. Value Investing Perspective - Value investors, like Warren Buffett, typically do not advocate for stop-loss based on price declines, as they view such declines as opportunities to buy more shares at a discount [17]. - Instead of price-based stop-loss, value investors should focus on fundamental changes in the investment thesis to determine when to exit a position [18][19].