Aversion to a Sure Loss
It’s the instinct to avoid to accept a definitive loss when there is still a chance of recovering it. This can lead to taking a riskier chance that might lead to an even larger loss. This also drives the sunk cost fallacy: continuing to invest in a failing course of action because walking away would mean acknowledging a loss.
In Prospect Theory terms, aversion to a sure loss reflects risk-seeking behaviour in the loss domain (the convex portion of the value function): a guaranteed small loss feels worse than a gamble that might produce either no loss or a larger loss.
The bad movie
Staying until the end of a bad movie in the cinema because you already paid for the ticket, even though it results in a further loss of time. In this case, the ticket price is a sunk cost that cannot be recovered; the rational decision would be to evaluate only whether sitting through the rest of the film is worth your time from this moment forward. But leaving would confirm the loss; staying preserves the hope that it might get better.
Also relates to: Diminishing Sensitivity · Loss Aversion · Myopic Loss Aversion · Gambler’s Fallacy