A good rule - which leads me on to say how suspicious I am about methodologies that seem so subjective and case- and time-specific that they can't be reliably backtested. Particularly in daytrading - where a quick decision for some traders seems to count more than a reliable principle.
OK, all our aim is to make money, and making a profit by any trading means is a good outcome. But if your method is random, your reward will be random. Long-term, what's good about that?
