◐ Behavioral
◆ The PatternContinuing an action because of previously invested resources (time, money, effort) rather than future value.
The sunk cost fallacy — continuing a course of action because of past investment, rather than future expected value.
Past cost = irrelevant → Only future costs and benefits should drive decisions
In trading:
• "I've already lost $5K — I can't sell now" → the $5K is gone either way
• "I've spent 6 months researching this company" → past time doesn't change future outlook
• Doubling down on a loser to "make it back" → escalation of commitment
• "I've already lost $5K — I can't sell now" → the $5K is gone either way
• "I've spent 6 months researching this company" → past time doesn't change future outlook
• Doubling down on a loser to "make it back" → escalation of commitment
Rational rule: ignore what you can't change (past), decide based on what you can (future).
Pattern bridge: Weighting past investment that can’t be recovered. In ML, early stopping fights sunk-cost thinking: stop training even though you’ve invested epochs.