价格变化率（ROC）

ROC 是动能指标的优化版本——它是围绕零轴波动的曲线。

交易信号
ROC 的交易信号与动能指标交易信号一致。

横盘市场
首先，你需要根据自己对以往横盘价格走势的观察，设置超买和超卖标准。通常，该标准需要囊括2/3ROC的最高点和最低点。
• 当ROC向下穿过超卖区回调之后，做多。
• ROC向上穿过超买区后回调，做空。
• 出现看跌背离后做空——前期ROC高点位于超买区之上。

示例1
联邦快递股票以及  10 日 ROC 指标    21 日EMA。

 
1. [S] 处做空——价格从超买区域回调。在前期高点附近设置止损。
2. [L] 处做多——价格从超卖区回调。在前期低点附近设置止损。
3. [S] 处做空。
4. [L] 处做多。经证实，该信号为错误信号。价格跌破前期低点，做多订单止损。
5. [L] 处做多——ROC从超卖区域上升。
6. [S] 处做空。
所有单子都应设置止损。
 
趋势市场
首先，利用趋势过滤器来确认趋势方向。在上升趋势中，ROC趋向于在零轴上方，下降趋势中，ROC则倾向于在零轴下方。只有当交易信号与趋势一致才可靠。
• 在上升趋势中，如果ROC从零轴下方上升，则做多。
• 在下降趋势中，如果ROC从零轴上方下降，则做空。
利用止损买入/卖出来确认进出场时机。利用趋势过滤器，当趋势线出现背离时平仓获利。趋势线有时根据ROC得出。ROC趋势线的改变通常早于价格图表趋势线。

示例 2
通用汽车股价走势以及  10 日ROC 、    21 日EMA。

 
1. ROC 从零轴之下上升，在上升趋势中给出了一个很好的入场信号。[L] 处做多。
2. [P] 处出现看跌背离，平仓获利。
3. 三重看跌背离出现——[P] 处进一步平仓获利。[X] 处当价格收于MA下方平仓。
4. [L] 处当ROC从零轴下方上升，收盘价位于MA上方并且高于信号日——做多。
5. [P] 处看跌背离，部分平仓。[X] 处价格收于MA下方，全部平仓。

公式
ROC的计算公式如下:
           (今日收盘价 – n日前的收盘价) / n日前的收盘价* 100 %
这可以让指标围绕0轴周围波动。

示例

 
Rate of Change (Price)
ROC is a refinement of Momentum - readings fluctuate as percentages around the zero line.
The indicator is designed for use in ranging markets - to detect trend weakness and likely reversal points. However, when combined with a trend indicator, it can be used in trending markets.
Trading Signals
ROC trading signals are identical to Momentum signals.
Ranging Markets
First, you will need to set overbought and oversold levels based on your observation of past ranging markets. The levels should cut across at least two-thirds of the peaks and troughs.
• Go long when ROC crosses to below the oversold level and then rises back above it.
• Go long on bullish divergences - where the first trough is below the oversold level.
• Go short when ROC crosses to above the overbought level and then falls back below it.
• Go short on a bearish divergence - with the first peak above the overbought level.
EXAMPLE 1
FedEx is plotted with    10 day ROC indicator and    21 day exponential moving average.
1. Go short [S] when ROC turns down above the overbought level. Place a stop-loss above the recent High.
2. Go long [L] when ROC turns up from below the oversold level. Place a stop below the latest Low.
3. Go short [S].
4. Go long [L]. This proves a false signal as price falls below the recent Low - stopping out the position.
5. Go long [L] when ROC again turns up from below the oversold level.
6. Go short [S].
Use stop-losses on all trades.
Trending Markets
First, identify the trend direction using a trend indicator. ROC tends to stay above zero during an up-trend and below zero during a down-trend.
Only take signals in the direction of the trend.
• In an up-trend, go long if ROC turns upwards when below zero.
• In a down-trend, go short if ROC turns downward when above zero.
Use trailing buy and sell stops to time your entry and exit. Take profits on divergences and trend line breaks. Exit using a trend indicator.
Trend lines are sometimes drawn on ROC. A break in the trend line often occurs in advance of a similar break on the price chart.
EXAMPLE 2
General Motors with    10 day ROC and    21 day exponential moving average.
1. ROC turns up from below zero, providing an excellent first entry point in the trend. Go long [L].
2. Take profits [P] on a bearish divergence.
3. A triple divergence occurs - take more profits [P].
Exit [X] when price closes below the MA.
4. Go long [L] when ROC turns up below zero. Enter when price crosses above the MA and above the High of the signal day.
5. Take profits [P] on a bearish divergence.
Exit [X] when price closes below the MA.
Formula
Rate of Change is calculated as:
         (Closing Price [today] - Closing Price [n days ago]) / Closing Price [n days ago] * 100 %
This causes the indicator to fluctuate as a percentage around the zero line.

文章翻译由兄弟财经提供

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