How clever financial scammers make a group of people believe 100% in themselves? Actually, the method is not to improve their predictive ability but to use filtering. Suppose someone sends messages to 500 friends, informing half that a certain stock will rise and the other half that it will fall. The next day, regardless of how the market moves, they only keep those who received correct information, then divide them into two groups to continue predicting. After several rounds, although the vast majority have been eliminated, there will always be a small group of people who see him "accurately hit" multiple times. In the eyes of these people, this person has never been wrong, as if he truly has the ability to predict the future, while they don't realize they are just survivors filtered by probability. So, when this person starts selling courses or advice, these people believe wholeheartedly because they have witnessed "continuous success." This is not because he is truly skilled, but because they only see the successful records that were kept, and do not see the failed cases that have already disappeared.