Welles Wilder RSI (I Chart) The RSI chart uses one adjustable parameter, P (The number of days averaged). The calculations are based on day-to-day changes in Adjusted Price.
Calculate an initial RSI using a simple average:
- Calculate the Simple Average of the Positive changes in value and another simple Average of Negative changes in value.Both for P number of days.
- AvgDwn = Sum Positive / P
- AvgUp = Sum Negative / P
- Calculate the initial RSI using the Simple Averages of the Positive and Negative changes (This will be the RSI value for day P).
- Initial RSI = 100 – [ 100 / ( 1 + ( AvgUp / AvgDwn ) ) ]
Calculate the remaining AvgUp and AvgDwn values using an Exponential Average for Days > P
- AvgUp = [(Previous AvgUp * (P-1)) + Today’s Negative Change] / P
- AvgDwn = [(Previous AvgDwn * (P-1)) + Today’s Positive Change] / P
Calculate the RSI for Days < P
- RSI = 100 – [ 100 / ( 1 + (AvgUp / AvgDwn) ) ]
FastTrack sets any value of RSI that is less than 1 to 1. This is unique to FastTrack and has no impact on the practical interpretation of the chart.