Confidence is the necessary fuel for transaction execution. If it is too high, people will ignore risks, and if it is too low, people will miss planned opportunities. This article analyzes the costs of both ends of confidence from the perspective of trading psychology, discusses how confidence should come from familiarity with methods and long-term records rather than recent profits and losses, and provides practical calibration methods such as judgment accuracy and distinguishing evidence-based confidence from perceived confidence, so that confidence can follow evidence rather than emotions, thereby striking a balance between plan execution and risk control. The content is for reference only and does not constitute investment advice.