3906 serves as a deterrent for the bulls to push the price higher. The power of this trend line helps us traders not to act before the market moves. Had you allow your own bias and cloud your judgement, you might have already bought into it and while you could be right later on, for now you are also tying up your capital and not earning a profit as well.
In short, increase your odds of success with the trend lines. The rules are pretty straightforward but like most humans, we tend to outsmart ourselves and try to bend the system and want things to accelerate at our pace. Such naivety and lack of experience will have to pay a price of holding on , suffer paper loss , etc.