该指标由Alexander Elder博士研发而来，用于测量市场中买方和卖方的压力。它既可以单独使用也可以和三重滤网过滤系统结合起来使用。Elder利用13日指数移动平均线（EMA）来反映市场达成的价值共识。牛市力量是用来衡量买方关于推动价格上升达成的共识力量，而熊市力量反映的则是卖方将价格拉低的力量。牛市力量是由当日的最高价减去13日的EMA得出，而熊市力量是由当日的最低价减去13日EMA计算而来。
交易信号
单独使用的时候，艾达透视指标需要3个窗口：
1. 价格的K线图以及13日指数移动平均线。
2. 艾达透视指标牛市力量。
3. 艾达透视指标熊市力量。
始终要追随趋势交易——趋势可以通过13日EMA判断出。
• 当熊市力量位于零以下，并出现看涨背离时做多。
• 牛市力量位于零之上，出现看跌背离时做空。
进一步的交易规则，可以在Elder 博士的《以交易为生》一书中找到。
如果你想实现快速的盈利：
• 每当熊市力量跌破零线之后而向上翻升时增加多头头寸。
• 每当牛市力量穿透零线之后反转为负数时增加空头头寸。
示例：
澳大利亚普通股指数以及 13日EMA， 艾达透视指标。
1. [S] 处牛市力量出现看跌背离，做空。等待EMA向下倾斜。
2. [L] 处熊市力量出现看涨背离，做多。等待EMA向上倾斜。
3. 牛市力量出现看跌背离，但此时不建议进场——EMA没有向下倾斜。
Elder Ray Index
Developed by Dr Alexander Elder, the Elder-ray indicator measures buying and selling pressure in the market. The Elder-ray is often used as part of the Triple Screen trading system but may also be used on its own.
Dr Elder uses a 13-day exponential moving average (EMA) to indicate the market consensus of value. Bull Power measures the ability of buyers to drive prices above the consensus of value. Bear Power reflects the ability of sellers to drive prices below the average consensus of value.
Bull Power is calculated by subtracting the 13-day EMA from the day's High. Bear power subtracts the 13-dayEMA from the day's Low.
Trading Signals
When used on its own, the Elder-ray requires 3 screens:
1. A bar chart with 13-day exponential moving average;
2. Elder Ray Bull Power; and
3. Elder Ray Bear Power.
Only trade in the direction of the trend - indicated by the slope of the 13-day EMA.
• Go long if Bear Power is below zero and there is a bullish divergence.
• Go short if Bull Power is above zero and there is a bearish divergence.
Further trading rules can be found in Trading For A Living by Dr Alexander Elder.
If you wish to pyramid your position:
• Increase your long position whenever Bear Power dips below zero and then rises back into positive.
• Increase your short position whenever Bull Power rises above zero and then falls back into negative.
EXAMPLE
The All Ordinaries Index (Australia) is shown with 13-day exponential moving average (EMA) and Elder Ray Bull & Bear Power.
1. Go short [S] on bearish divergence on Bull Power. Wait for the EMA to turn downwards.
2. Go long [L] on bullish divergence on Bear Power. Wait for the EMA to turn upwards.
3. Bearish divergence on Bull Power but no trade is entered - the EMA does not turn down.
本文翻译由兄弟财经提供
文章来源：http://www.incrediblecharts.com/indicators/elder_ray_index.php