長期形態二、雙重頂和雙重底結構

雙重頂：雙重頂有兩個類似高度的高點和對前一次低點的突破。雙重頂並不是交易的可靠依據，因為雙重頂和三重頂的類似性並且交易範圍有限。
突破後的做空目標應該為峰高和底部之間的距離。
 
成交量確認：第二輪波峰處的成交量減少，在突破支撐位後成交量增加。
交易信號：在突破支撐位後做空，並在上一波峰處的價位設置止損。價格通常會反彈到支撐位，而這時支撐位變成阻力位。在價格走勢在該阻力位向下反彈時做空，並在支撐位上方設置止損。

雙重底

同樣，雙重底結構也不是交易的可靠依據，因為其類似於三重底結構和交易範圍。
當價格突破阻力位時，做多目標為雙底和頂部之間的垂直距離。
 
成交量確認：在價格回調時成交量減少，在觸及支撐位後成交量迅速增加。
交易信號：在價格越過阻力位後做多，並在上一輪的低點處設置止損。價格之後會反彈，阻力位也相應的變為支撐位。當價格越過支撐位後做多，並在該支撐位設置止損。

Double Tops and Double Bottoms
Double Tops
Double tops are identified by two peaks of similar height, followed by a break below the level of the intervening trough. They are treacherous to trade, partly because of their similarity to triple tops and trading ranges.
The target for a breakout move is measured vertically from the highest peak to the support line drawn through the intervening trough. This is then projected downwards from the breakout point.
Volume confirmation
Reduced volume on the second peak followed by increased volume on the break below the support line.
Trading Signals
Go short on a break below the support line.
Place a stop-loss just above the last peak.
Price often rallies back to the support line which then acts as a resistance level. Go short on a reversal signal and place a stop-loss just above the resistance level.
Double Bottom
Double bottoms are also treacherous to trade, in part because of the similarity to triple bottoms and trading ranges.
The target is measured from the lowest trough to the level of the intervening peak. It is then projected up from the break out above the resistance line.
Volume Confirmation
Reduced volume on the second trough followed by increased volume on the break above the resistance line.
Trading Signals
Go long on a break above the resistance line.
Place a stop-loss just below the last trough.
Price often corrects back to the resistance line which then acts as a support level. Go long on a reversal signal and place a stop-loss just below the support level.

本文翻譯由兄弟財經提供

文章來源：http://www.incrediblecharts.com/technical/double_tops.php