Trading Bollinger bands

Bollinger Bands
"Trading bands are one of the most powerful concepts available to the technically based investor, but they are not, as is commonly believed, give absolute buy and sell signals based on price touching the bands. What they do is answer the perennial question of whether The prices are high or low on a relative basis. Armed with this information, an intelligent investor can buy and sell decisions by using indicators to confirm price action.
But before we begin, we need a definition of what works. Trading bands are lines plotted in and around the cost to form struktura''plikot. It is the action of prices near the edges of the envelope that we are particularly interested in ...."
Taken from stocks and commodities, ext. 10:02 (47-51): Using Bollinger Bands by John Bollinger
For further interpretation concerning the above article found in the February 1992 issue of Technical Analysis of stocks and commodities.
Bollinger bands are embedded in MetaStock ™, however you may want to use individual custom formulas.
Custom formulas for the components of the Bollinger bands are as follows:
The upper range:
MOV (C, 20 C) + (2 * (std (C, 20)))
Lower Band:
MOV (C, 20 C) - (2 * (std (C, 20)))
Middle Band:
MOV (C, 20 C)
% B:
((C +2 * STD (C, 20) - mov (C, 20, S)) / (4 * STD (C, 20))) * 100
Band width:
((MOV (C, 20 C) + (2 * (std (C, 20)))) - (MOV (C, 20 C) - (2 * (std (C, 20 )))))
/ MOV (C, 20 C)