布林动量指标以及布林波幅指标

约翰•布林在他的网站上描述了布林动量指标（Bollinger %b indicator）。布林带（Bollinger Bands）是根据20日简单移动平均线加/减2倍标准差得出。布林动量指标显示了收盘价与布林带的关系。布林在其网站上也描述了另外一个独立的指标：布林波幅指标（Band Width Indicator），它可以反映布林带的宽度。

布林动量指标交易信号

布林描述了以下可用于市场处于上升/下降趋势中或处于调整期的交易信号：

趋势市场

• 如果布林动量指标回撤到负值（比如，收盘价位于布林带下方），并且第二次回撤布林动量指标为正值，则应做多。
• 如果布林动量指标反弹大于100（收盘价位于布林带上方），并且第二次反弹低于100，则做空。
利用威尔斯怀尔德的相对强弱指数所显示的失败的震荡（failure swings）来确认信号。

示例：

高盛集团股价以及20日布林动量指标。

1. [L] 处做多：前一波布林动量指标最小值低于0，而这次回撤最小值大于0。
2. [X] 处平仓：之前布林动量指标反弹大于100，而这次反弹没有突破100.
3. [L] 处做多：前一波布林指标回撤达到0，而这次位于0之上。
4. [X] 处平仓：布林动量指标从100以上持续下跌，出现空头背离。

布林波幅指标（Band Width Indicator）

布林波幅指标（Band Width Indicator）可以对趋势波动性的变化发出预警。布林带变窄之后，接下来通常会伴随着波动量的快速增加。布林波幅变窄，对应的布林波幅指标低于2.0%。S&P 500指数的布林波幅指标小于2%时会导致很多的投机行为，但需要惊醒的是，市场在真实的趋势开始前，通常会先开始一个假动作。

 高盛将显示20日保历加通道宽度。

示例：

  高盛集团股票已经20日布林波幅指标。
 
1. [L] 处做多：布林波幅指标在收缩到历史低点后开始上升。
布林波幅指标要求波动收缩在2.0%以下，但是较宽的缩幅也可以提供足够完美的交易信号。

布林动量指标设置

布林动量指标以及布林波幅指标的默认设置为20日简单移动平均线加/减2倍标准方差。
布林动量指标公式为：（收盘价 – 上布林线）/（上布林线– 下布林线）。
布林波幅计算公式为：（上布林线–下布林线）/同一时期的简单移动平均线。

Bollinger %b Indicator - and Band Width Indicator
Bollinger %b is described by John Bollinger on his website. It indicates the position of Closing Price relative to Bollinger Bands® plotted at 2 standard deviations around a 20-Day simple moving average. Bollinger also describes a separate Band Width Indicator that reflects the width of the Bollinger Bands.
Bollinger %b Trading Signals
Bollinger describes the following signals which can be used in a trending or ranging market:
Trending Market
• Go long if a retracement records a negative number on %b (i.e. price has closed below the lower Bollinger Band) and is followed by a second retracement where %b remains positive.
• Go short if a rally records a value above 100 for %b (the upper Bollinger Band) and is followed by a second rally where %b remains below 100.
Use failure swings on Welles Wilder's Relative Strength Index to confirm the signals.
EXAMPLE
Goldman Sachs is displayed with 20-day Bollinger %b.
1. Go long [L] when a retracement on Bollinger %b respects the zero line after the previous retracement was below zero.
2. Exit [X] when a rally on Bollinger %b falls short of 100 after the previous rally exceeded 100.
3. Go long [L] when the retracement on Bollinger %b reverses while above zero after the previous retracement reached zero.
4. Exit [X] after another bearish divergence on Bollinger %b, from above to below 100.
 
Bollinger Band Width Indicator
Bollinger's Bandwith Indicator is used to warn of changes in volatility. As we know from using Bollinger Bands, a squeeze where the bands converge into a narrow neck often precedes a rapid rise in volatility. A Bollinger Band squeeze is highlighted by a fall in the Band Width indicator to below 2.0%. Bollinger claims that a drop below 2% on the S&P 500 has led to many spectacular moves, but warns that the market often starts with a fake move, in the wrong direction, before the real move commences.
 

 
EXAMPLE
Goldman Sachs is displayed with 20-day Bollinger Band Width.
1. Go long [L] when Bollinger Band Width starts to rise after contracting to a historic low.
Bollinger requires contractions below 2.0%, but wider contractions provide perfectly adequate signals.
Bollinger %b Setup
The default setting for Bollinger %b and Band Width is a 20-Day simple moving average with bands drawn at 2 standard deviations.
See Indicator Panel for directions on how to set up an indicator — and Edit Indicator Settings to change the settings.
Bollinger %b Formula
The forumula for Bollinger %b is (Closing Price - Lower Band) / (Upper Band - Lower Band).
The formula for Bollinger Band Width is (Upper Band - Lower Band) / Simple Moving Average for the same period.

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