Developed by J. Welles Wilder, the Relative Strength Index (RSI) is a momentum oscillator that measures the speed and change of price movements. The classic way to interpret RSI is to look for oversold levels below 30 and overbought levels above 70.

Period: RSI period in bars
offset: 0-100 (optional, defaults to 0)
series: optional, see below


RSI = 100 - ( 100 / (1 + RS))
RS = (average of N up closes) / (average of N down closes)
N = period in bars (typically 14)

RSI is calculated as a series that smooths the impact of large price movements. The RS is calculated using moving averages that are smoothed by previous averages, as explained here: Invest Excel: Relative Strength Index. The more data points that are used to calculate the RSI, the more accurate the results. We use up to 100 bars prior to the first bar (assuming that much exists), which is a compromise between accuracy and performance.


You can use the offset parameter to spot divergence in the RSI and the price action. To screen for RSI(14) > 70, and has increased from the value 10 bars ago, enter:

RSI(14,0) > 70 And RSI(14,0) > RSI(14,10)

You can calculate the benchmark RSI to create a market timing signal. For example to exit all positions when the market is overbought (RSI > 70) enter the following sell rule:

RSI(14,0,#Bench)>70

Series Parameter

By default, technical functions access the time series of the instrument in context. You can specify a different time-series in several ways like: using GetSeries(), specifying a StockID directly, or using a time series id. See the examples below.

Examples

Get the latest close price using Close(0, series) using different methods for different time series.

Using the ID directly
Using the StockID for SPY:USA*	Close(0, 24262)
For the Industry series of the stock being evaluated	Close(0,#Industry)
Using a Time Series Id	Close(0,$RUI)
For the benchmark	Close(0, #Bench)
Using GetSeries
Using a fully qualified ticker	Close(0, GetSeries("SPY:USA"))
When USA is your default	Close(0, GetSeries("SPY"))
See GetSeries() for more examples like for aggregate series
* StockIDs never change

 

Predefined Series IDs

These are special series ids. Additional Series Ids can be found in the reference under: MISC→TIME SERIES IDs

Id	Description	Freq	OHLC
Industry and Sector
#Sector	Stock's Sector	Daily	C
#SubSector	Stock's SubSector	Daily	C
#Industry	Stock's Industry	Daily	C
#SubIndustry	Stock's SubIndustry	Daily	C
Miscellaneous
#Bench	Benchmark closing prices	Daily	C
#TNX	10Y Treasury Note	Daily	OHLC
FED Model series (chart)
#SPRP	SP500 Risk Premium	Weekly	C
#SPEPSCY	SP500 EPS CurrentY	Weekly	C
#SPEPSNY	SP500 EPS NextY	Weekly	C
#SPEPSCNY	SP500 EPS Blend Y	Weekly	C
#SPEPSQ	SP500 EPS Blend Q	Weekly	C
#SPEPSTTM	SP500 EPS Trailing 12 months	Weekly	C
#SPYield	SP500 Yield	Weekly	C

 

Special Series Ids for Moving Averages & Highest/Lowest functions

Id	Description	Context
#Open	Open prices	Stock & ETF
#High	High prices	Stock & ETF
#Low	Low prices	Stock & ETF
#Vol	Volumes	Stock & ETF