The Sunk-Cost Fallacy
Holding a loser because you have "already lost so much" — throwing good money after bad.
The sunk-cost fallacySticking with something because of what you’ve already invested. is the tendency to continue something because of what you’ve already invested in it — money, time, or effort — rather than because it makes sense going forward. In investing, it’s the voice that says “I’ve already lost so much on this, I can’t sell now.”
The key principle that dissolves the fallacy: money already spent is gone and irrelevant — only the *futureA binding agreement to buy or sell at a set price on a future date.* prospects of a decision should matter. A “sunk costSticking with something because of what you’ve already invested.” is a cost you can’t recover no matter what you do next; rationally, it should have zero weight in deciding whether to continue. But emotionally (powered by loss aversionA loss hurts about twice as much as an equal gain feels good. and anchoring), we treat past investment as a reason to keep going, to justify what we’ve already putThe right, not the obligation, to buy or sell at a set price. in — “throwing good money after bad.” In investing this shows up as: holding (or worse, averaging down into) a deteriorating stock because “I’ve already lost 40%, selling now makes it real,” or sticking with a failing strategy because “I’ve putThe right, not the obligation, to buy or sell at a set price. so much time into it.” The deterioration of the business, not your accumulated loss, is what matters. The clean mental test: *“if I had this money in cash today, would I putThe right to sell the underlying at a set price — a bearish bet. it into this investment right now?”* If the answer is no, the only thing keeping you in is the sunk costSticking with something because of what you’ve already invested. — and that’s a reason to exit, not to stay. Past losses are a tuition you’ve already paid; don’t pay more just to honour them.
- What it is — continuing because of what you’ve already putThe right, not the obligation, to buy or sell at a set price. in, not because it makes sense going forward.
- The principle — sunk costs are gone and irrelevant; only *futureA binding agreement to buy or sell at a set price on a future date.* prospects should drive the decision.
- It causes — holding/averaging down into losers “to not make the loss real,” sticking with failing strategies for the time invested.
- The test — “would I buy this today with fresh cash?” If no, the sunk costSticking with something because of what you’ve already invested. is the only thing keeping you in — so exit.
ExampleA stock you bought at ₹1,000 is now ₹600 with worsening fundamentalsValuing a company from its business and financials.. The sunk-cost voice says “I’ve already lost ₹400, I can’t sell now — maybe I’ll even buy more to average down.” But the ₹400 is gone regardless. The real question: would you buy this deteriorating business at ₹600 with fresh money? If no, holding (or adding) just throws good money after bad. Exit and redeploy where the futureA binding agreement to buy or sell at a set price on a future date. is better.
Key takeawayThe sunk-cost fallacySticking with something because of what you’ve already invested. keeps you in a losing investment because of what you’ve already putThe right, not the obligation, to buy or sell at a set price. in — but spent money is gone and irrelevant; only *futureA binding agreement to buy or sell at a set price on a future date. prospects should decide. It drives holding/averaging-down into losers “to not realise the loss.” Apply the test: would you buy this today* with fresh cash? If no, the sunk costSticking with something because of what you’ve already invested. is the only thing holding you — so exit.
FAQs
How is this different from just being patient with a long-term investment?
Patience is justified when the *future* prospects (the thesis) remain sound — you hold because the business is still on track, not because of past losses. The sunk-cost fallacy is holding a *deteriorating* investment *because* of what you’ve lost. The distinction: patience is forward-looking (thesis intact), sunk-cost is backward-looking (anchored to past losses). Judge by the future, not what you’ve already paid.