The Sunk Cost Fallacy in Investing: Why You Cannot Cut Losses
The sunk cost fallacy makes investors hold a loss just because they have put money in, instead of deciding based on the future. We explain the psychology, examples, and how to escape this trap.
"I have put so much in already, I cannot quit now"
This is one of the most dangerous sentences in investing. It is a symptom of the sunk cost fallacy — a psychological trap that makes you hold a loss just because you have invested in it, instead of deciding based on what is reasonable for the future.
What sunk cost is
A sunk cost is money (or time, effort) already spent and unrecoverable. The sunk cost fallacy is the tendency to let those losses drive current decisions — when they should not.
The flawed logic: "I have invested a lot, quitting now would be a waste." In reality, the money lost is already lost, whether you hold or sell. The right decision must be based on: from here on, is holding or selling better?
Examples in investing
- You bought a stock at 100, now it is 60. The business has clearly deteriorated, but you do not sell because you are "waiting to get back to 100" — only because you do not want to admit the existing loss.
- You poured money into a failing crypto project, then put in more to "recover," because you regret the amount already spent.
In both, the decision is driven by money already spent (sunk cost), not by future prospects.
Why this trap is so strong
- Loss aversion: humans hate admitting losses. Holding a loss delays the pain of "realizing" it — even though that can make the loss worse.
- Desire for consistency: abandoning an investment feels like admitting the original decision was wrong, which the ego dislikes.
- Irrational hope: "maybe it will recover" — clinging to hope instead of a clear-headed assessment.
This is a close cousin of the inability to cut losses and part of the trading psychology to overcome.
How to escape the sunk cost trap
- Ask the right question: instead of "How much have I lost?", ask "If I did not own it today, would I buy it at this price?" If the answer is no, that is a sign to consider selling.
- Separate the past from the current decision: the money spent is a sunk cost — it is the same whether you hold or sell. Only the future matters.
- Decide your stop-loss criteria IN ADVANCE: set a stop loss with a clear head, so you do not have to fight emotion when the market is red.
- Use automated tools: automatic TP/SL executes your predefined decision without the sunk cost bias interfering.
Note: not every loss must be sold
Be careful not to confuse: escaping the sunk cost bias does not mean selling every time you see a loss. For long-term investing in good assets, a temporary drop is not a reason to sell (see time in the market). The crux is: decide based on the asset''s future prospects, not on the money you have already put in.
Conclusion
The sunk cost fallacy makes you hold a loss just because you have invested in it, instead of deciding based on the future. Money already lost is lost — it should not drive your current choice. Ask "if I did not own it, would I buy at this price?", separate the past from the decision, and set stop-loss criteria in advance so emotion does not drive you.
Next step
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