Now Bollinger did talk about varying the width parameters (the SD), depending on your periods:
Period 10 == use 1.9 SD
Period 20 == use 2.0 SD
Period 50 == use 2.1 SD
He says this keeps the containment percentage between 88-89% in most markets.
He also talked about using multiple SDs with the same period (as we are discussing above), and also to try overlaying different periods with the same SD to see where different points intersect... he didn't elaborate about much in his book about these, but just pointed out they might be interesting for more advanced TA folks.
Period 10 == use 1.9 SD
Period 20 == use 2.0 SD
Period 50 == use 2.1 SD
He says this keeps the containment percentage between 88-89% in most markets.
He also talked about using multiple SDs with the same period (as we are discussing above), and also to try overlaying different periods with the same SD to see where different points intersect... he didn't elaborate about much in his book about these, but just pointed out they might be interesting for more advanced TA folks.