简易波动指标（EMV）

简易波动指标（Ease of Movement ）是由Richard W Arms开发，原理类似于等成交量图。它突出了成交量与价格之间的关系，可以非常有效的衡量趋势的强度。

该指标表现了：
• 如果较少的成交量就能推动股价上涨，则EMV数值会升高；
• 如果股价下跌时也仅伴随较少的成交量，则EMV数值将降低；
• 如果价格波动小，或者价格的上涨和下跌都伴随着较大的成交量时，则EMV的数值会趋近于零。意味着价格的分散（卖方市场）或集聚（买方市场）。

交易信号

交易信号通常是由EMV指标窗口中的指数移动平均线（EMA）得出。它们在趋势交易中效果显著。
• EMV自下而上穿透零轴时做多。
• EMV自上而下穿透零轴时做空。

示例：

可口可乐公司股价以及 EMV、 10日EMA. 

1. [L] 处做多：EMV上穿到零轴之上。
2. [S] 处做空：EMV穿至零轴之下。
3. [S] 处做空：需要注意的是，我们在市场调整期频繁的被扫损。

计算公式
EMV的计算步骤为：
1. 计算每日价格的中值。
           (最高价 + 最低价) / 2
2. 计算出中值的波动：
          今日的中值—昨日的中值
3. 计算出等成交量柱状图的高与宽的比值：
           成交量（百万）/（最高价—最低价）
4. EMV值为：
           中值的变动量 / 长宽比
5. EMV通常结合14日EMA使用。

Ease of Movement
Ease of Movement was developed by Richard W Arms and performs a similar function to Equivolume charts. It highlights the relationship between volume and price changes and is particularly useful for assessing the strength of a trend.
The indicator shows:
• high positive values when prices move upward on light volume;
• high negative values when prices move down on light volume;
• low values if price is not moving or if it takes heavy volume to move prices, signaling distribution oraccumulation.
Trading Signals
Signals are normally taken from an exponential moving average plotted on the Ease of Movement indicator. They are more effective in a trending market.
• Go long when Ease of Movement crosses to above zero (from below).
• Go short when Ease of Movement crosses to below zero (from above).
EXAMPLE
Coca Cola Corporation plotted with   Ease of Movement indicator smoothed by a
  10 day exponential moving average.
1. Go long [L]: Ease of Movement crosses to above zero.
2. Go short [S]: Ease of Movement crosses to below zero.
3. Go long [L]: Ease of Movement crosses to above zero.
4. Go short [S]: Ease of Movement crosses to below zero.
5. Go long [L]: Ease of Movement crosses to above zero.
6. Go short [S]: Note that we are whipsawed more frequently in a ranging market.
Setup
The Ease of Movement default is set at 10 days smoothing by an exponential moving average. To alter the default settings - Edit Indicator Settings.
See Indicator Panel for directions on how to set up an indicator.
Formula
The steps in calculating Ease of Movement are:
1. Calculate the Mid-point for each day:
           (High + Low) / 2
2. Calculate the Mid-point Move for each day:
           Mid-point [today] - Mid-point [yesterday]
3. The Box Ratio determines the ratio between height and width of the Equivolume box:
           Volume [in millions] / (High - Low)
4. Ease of Movement is then calculated as:
           Mid-point Move / Box Ratio
5. Ease of Movement is normally smoothed with a 14 day exponential moving average.

本文翻译由兄弟财经提供

文章来源：http://www.incrediblecharts.com/indicators/ease_of_movement.php