Trading bands, which are lines plotted in and around the price structure to form an envelope, are the action of prices near the edges of the envelope that we are interested in. It's not the newest of ideas, but as John Bollinger of Bollinger Capital Management points out, it's one of the most powerful concepts available to the technically based investor, answering not whether absolute buy and sell signals are being given but whether prices are high or low on a relative basis. Trading bands can forewarn whether to buy or sell by using indicators to confirm price action. How do trading bands work? Bollinger, of Bollinger Bands fame, explains how.