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Elder Ray Index (Bull Power and Bear Power)
Two indicators measuring how far a period's high and low sit above and below an EMA, used to gauge buying and selling pressure relative to trend.
The Elder Ray Index, developed by Alexander Elder, consists of two separate readings: Bull Power, which measures how far a period's high price sits above a chosen EMA, and Bear Power, which measures how far a period's low price sits below that same EMA.
Together, they're intended to gauge buying and selling pressure specifically relative to the prevailing trend (represented by the EMA), rather than in isolation — for example, Bear Power turning less negative during an uptrend is commonly read differently than during a downtrend. See Kaavon's dedicated Elder Ray article for the full calculation.
Examples
- Bull Power and Bear Power are both measured relative to the same underlying EMA, which represents the prevailing trend.
- Bear Power turning less negative while an uptrend's EMA continues rising is a commonly cited example of combining the two readings with trend context.