In the last fifteen minutes of the day, you must make up your mind as to what you are going to do. If the odds are in favor of an uptrend continuing, you must immediately buy. The idea is to buy high and sell higher. Of course you will not be right all the time. If your judgment is proven wrong the next day, you quickly make your exit at a small loss.
The key to success in trading is to make you losses small and your gains big. If you cannot cut losses quickly, never attempt trading. Your goal is to make money, and not after the excitement.