Quote from NoDoji:
I don't understand how Bollinger bands describe what has happened. I categorize BBs as an indicator, indicating the level at which price is or will be a certain deviation from a moving average.
Price tells us what has happened.
What do the Bollinger bands on your chart say happened that a price excursion itself fails to tell us?
I know of nothing that's predictive. Good news can spark a selloff, bad news can spark a rally; inside information is only as good as the reliability of the source; indicators, moving averages and trend lines offer frameworks around which probabilities can be tested.
What is an example of something that's predictive in the sense of the definition "to make known in advance"? Obviously anyone can predict anything, but what would be accurately predictive with regard to the market other than probabilities?