平滑变动率（S－ROC）是舒兹曼（Fred G•Schutzman）于1991年4月发表在《期货杂志》中。作为一个振荡指标，SROC的作用类似于动能指标以及价格变化率指标，但是SROC指标避免了它们的一些缺陷：
• 变动率指标经过平滑之后波动性减少，给出相对较少的错误讯号。
• EMA保证SROC仅会对新数据反应一次。
平滑变动率首先计算13日EMA（收盘价），接下来计算EMA的21日变化率。

交易信号
交易规则与动能指标、价格变动率指标类似。

趋势市场
第一步，利用趋势指标确认市场走势。SROC指标上升趋势中通常在0轴上方，下降趋势中则倾向于在0轴下方。
只跟随市场趋势交易。
• 上升趋势中，如果SROC位于0轴下方且呈上升趋势时，做多。
• 下降趋势中，如果SROC在0轴上方，并且走势向下时做空。
如果交易信号产生时同时出现背离，那么该交易信号将更加可靠。利用趋势过滤器作为平仓信号也可以利用追踪买入止损和卖出止损作为开仓或平仓信号。

示例
澳大利亚证券交易所(ASX)股票，   21日EMA ，   平滑变动率。

 
1. [S] 处当SROC位于0轴上方走势向下时做空。等待EMA走势向下。[X] 处当价格收于EMA上方平仓。
2. [S] 处当SROC再次位于0轴上方且走势向下、出现看跌背离，做空。等待EMA走势向下。[X] 处当价格收于EMA上方平仓。
3. SROC 在0轴下方向上反转。此时不宜采取行动：EMA方向仍然向下。
4. [L] 处当SROC从0轴下上升，看涨背离完成，且EMA上升时做多。
5. SROC在0从上方下降但是EMA持续上升。[S] 处当价格最终收于EMA下方时，多单平仓并做空。

设置
SROC的默认设置是：13日EMA以及21日价格比率。

Smoothed Rate of Change
Smoothed Rate of Change was first introduced by Fred G Schutzman inFutures magazine, April 1991. The oscillator performs a similar function to the Momentum and Rate Of Change indicators but avoids some of the weaknesses:
• Because of the smoothing the indicator is less erratic and gives fewer false signals;
• The exponential moving average ensures that the indicator only "barks" once. See Momentum for more detail.
Smoothed Rate of Change (SROC) first calculates a 13-day exponential moving average of closing price. Then calculate a 21-day Rate of Change of the exponential moving average.
Trading Signals
Trading rules are similar to Momentum and Rate Of Change.
Trending Markets
First, identify the trend direction using a trend indicator. Smoothed Rate of Change 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 SROC turns upwards when below zero.
• In a down-trend, go short if SROC turns downward when above zero.
Divergences add strength to buy and sell signals.
Exit using a trend indicator.
Use trailing buy and sell stops to time your entry and exit.
 
EXAMPLE
Australian Stock Exchange Limited (ASX) is shown with    21-day exponential moving average (EMA) and   Smoothed Rate of Change.
1. Go short [S] when SROC turns down while above zero. Wait for the EMA to turn downwards. Exit the trade [X] when price closes above the EMA.
2. Go short [S] when SROC again turns down while above zero, completing a bearish divergence. Wait for the EMA to turn downwards. Exit the short trade [X] when price closes above the EMA.
3. SROC turns up while below zero. No action is taken as the EMA continues to slope downwards.
4. Go long [L] when SROC turns up while below zero, completing a bullish divergence. Wait for the EMA to turn upwards.
5. SROC turns down while above zero but the EMA continues to rise. Exit the long trade and go short at [S] when price eventually closes below the EMA.
Setup
See Indicator Panel for directions on how to set up an indicator. The default settings for Smoothed Rate of Change are:
• 13-day exponential moving average; and
• 21-day rate of change.
To alter the default settings - Edit Indicator Settings.

本文翻译由兄弟财经提供

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