Sunk cost trap refers to a tendency for people to irrationally follow through on an activity that is not meeting their expectations. This is because of the time and/or money they have already invested. The sunk cost trap explains why people finish movies they are not enjoying, finish meals that taste bad, keep clothes in their closet that they’ve never worn and hold on to investments that are underperforming. The sunk cost trap is also called the Concorde fallacy after the failed supersonic Concorde jet program that funding governments insisted on completing despite the jet’s poor outlook.