Livermore’s Core Stop-Loss Principles

1. Strictly limit the loss on any single trade to a small proportion of your capital
Livermore would not allow one trade to consume a large amount of his capital. After entering a position, if the market moved contrary to his judgment, he would exit decisively once the loss reached around 10%, never holding on stubbornly. He believed that once a loss grew larger, your mindset would be seriously held hostage, making it difficult to make objective decisions.

2. Do not argue with the market; the market is never wrong
When a loss occurs, it is not the market that is wrong—it is your judgment. Do not make excuses or hope for a rebound to get back to breakeven, and do not subjectively fantasize about a market reversal. Once the price action proves that your position is wrong, cut the loss immediately and admit that the trade has failed.

3. If a position does not become profitable immediately after purchase, be alert
After establishing a position, if the market does not quickly move in your favor, you should be extra cautious even if no major loss has appeared yet. Often, this itself is a signal. You do not necessarily have to wait until the loss reaches the threshold before exiting; a market that keeps failing to deliver profits is itself a risk.

4. Distinguish a pullback from a trend reversal, and do not get shaken out by minor fluctuations
A stop-loss does not mean cutting a position on every minor fluctuation. Trade in line with the broader trend and allow normal market pullbacks. Set the stop-loss below a key price level to filter out short-term noise, exiting only when the trend is genuinely broken and avoiding frequent stop-outs caused by volatility.

5. Set a trailing stop-loss even when a position has unrealized profits
A stop-loss is needed not only upon entry; profits also need to be protected. As the market rises, continually move the stop-loss higher to lock in paper profits. This prevents a reversal from giving back all the profits you had secured. This was also a lesson he learned after experiencing multiple major rises and falls.

6. Never average down a losing position
Do not add to a losing position to lower the average cost. Buying more as the price falls was a practice Livermore explicitly opposed. It can leave you increasingly trapped and turn a small loss into a devastating one.

Lessons from Reality

Even though he theoretically understood this stop-loss system, Livermore himself repeatedly violated the stop-loss rules he had established later in life—holding losing positions, failing to cut losses, and overtrading, ultimately resulting in enormous losses.

The rules are not difficult; the difficult part is being able to execute them decisively when the market is volatile.