Indicator lines show the accumulated sums of bulls and bears power for the user-defined period.
Bulls power is calculated by the following formula:
where the following applies:
Accordingly, the following formula is used for calculating the bears power:
where the following applies:
The red indicator line shows the bears power, and the blue line indicates the bulls power. The higher line shows the stronger side. The intersection of lines indicates trend change and is a good moment for opening a deal in the direction of the power that appeared to be above the other one.

Fig. 1. Change of an uptrend to a downtrend.
Update 22.09.2017
Translated from Russian by MetaQuotes Ltd.
Original code: https://www.mql5.com/ru/code/19142
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