When and How Should You Cut a Loss?

“When should I cut a loss?” is a common beginner question. Numbers help explain why stops exist and how to define their purpose.

Why limit a loss?

A stop-loss closes exposure at a predefined boundary before the loss grows further. The central issue is that larger losses require disproportionately greater gains to recover.

After a 50% decline, the remaining capital must double to recover. A stop aims to limit exposure to this recovery asymmetry.

Three ways to define a stop

① Percentage: Specify a number in advance, such as 7% below purchase price. This is simple and mechanical.
② Support or structure: Exit when price breaks a level that invalidates the chart structure.
③ Thesis invalidation: Exit when the original reason for buying, such as a catalyst or trend, disappears.

Whichever approach is used, define it before buying. Setting it afterward lets emotion influence the boundary.

Why is taking a loss difficult?

Loss aversion makes a loss feel more intense than a similar-sized gain. “It may recover if I wait” can therefore postpone an exit while damage grows. A pre-established rule and consistent execution help address that impulse. Deciding how much to allocate beforehand also makes the planned loss more manageable.

Key points

① Bigger losses are harder to recover: −50% requires +100%.
② Define a percentage, structural or thesis-based boundary before buying.
③ Follow the predetermined criteria rather than shifting them with emotion.

Caution

Numbers are illustrative and do not recommend a specific asset or trade. Investment decisions and responsibility remain yours.