Dynamic RSI Indicator for ThinkOrSwim (Free Download)

IndicatorFreeIntermediate48 min video225 lines of codeNov 3, 2019Updated Oct 21, 2026

A free Dynamic RSI for ThinkOrSwim: the RSI with Bollinger Bands, a yellow average, squeeze dots and automatic trend lines, as upper and lower studies.

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Overview

In this tutorial I build a Dynamic RSI indicator for ThinkOrSwim from code that one of our members, Keith, sent us. His RSI had a lot of lines on it. In the video we turn what he looks for into rules the code checks on every bar: Bollinger Bands on the RSI, a slower yellow average line, squeeze dots and automatic trend lines.

The free download has two studies. The upper study puts arrows, squeeze dots and overbought and oversold bubbles on your price chart. The lower study shows the RSI with all its lines and the trend line bubbles. It is for traders who already use the RSI and want fewer, clearer signals from it, and it includes Keith's cheat sheet of 5 trade entries.

Key Takeaways

The Dynamic RSI is a free ThinkOrSwim indicator that adds Bollinger Bands (14 bars, 2 standard deviations) and a yellow 14-bar average line to a 14-period RSI.
A bullish arrow needs the RSI at or below its lower band, the lower band at or below 45, and the RSI at or below 30. A bearish arrow needs the RSI at or above the upper band, the upper band at or above 55, and the RSI at or above 70.
Chart bubbles mark the bar where the yellow average crosses above 70 or below 30 (Enter Super Overbought or Oversold) and the bar where it crosses back (Exit).
Red squeeze dots print when the upper and lower bands on the RSI are 10 points or less apart.
The lower study draws automatic trend lines on the RSI over the last 150, 80 and 40 bars, adapted from trend line code by Mobius, with Long and Short bubbles on the 80-bar lines.

What Is the Dynamic RSI?

The Dynamic RSI is an RSI indicator for ThinkOrSwim with three layers on top: Bollinger Bands, a slower yellow average and automatic trend lines. Keith built the first version, and in Episode 10 of our How to thinkScript series I turned his chart notes into code.

The RSI (Relative Strength Index) is a momentum oscillator that J. Welles Wilder introduced in his 1978 book, New Concepts in Technical Trading Systems, the same book behind our Wilder's Momentum Concept indicator. It compares the average gain with the average loss over 14 bars by default and plots the result from 0 to 100. Readings above 70 are usually called overbought and below 30 oversold.

A standard RSI gives you one line and two fixed levels. The Dynamic RSI tracks four relationships on every bar, and each one shows up in a different place:

Relationship	What marks it	Where you see it
RSI vs its Bollinger Bands	Up and down arrows	Upper study, on the candles
Yellow average vs 70 and 30	Enter and Exit Super Overbought and Oversold bubbles	Upper study, at the close
Upper band vs lower band	Red squeeze dots	Both studies: at the close and on the 50 line
RSI vs automatic trend lines	Long and Short bubbles on the 80-bar lines	Lower study

The Patterns Keith Found on His Charts

The Dynamic RSI started as charts Keith marked up and emailed to us. Before writing any code, I pulled out the patterns he kept coming back to:

Trend lines on the RSI. Keith bought bounces off RSI trend line support and watched for breaks. Lines drawn by hand are subjective, so the indicator draws them for you.
Retests. More often than not, Keith says, the RSI comes back to retest a trend line it broke. The retest is the conservative entry.
Band breaks. On his charts, RSI breaks above the upper band came before moves lower, and breaks below the lower band before moves higher. One of his notes says to cover a short when the RSI hits the lower band or turns back above the middle line.
The yellow average. It is far slower than the RSI, so a cross into overbought or oversold shows emphasis behind the move.
Timeframes. For scalping, Keith found a 4-minute chart a little cleaner than a 5-minute chart.

Keith also uses the Dynamic RSI to add confidence to Volatility Box trades and to find extra scalps when the market chops sideways.

How to Add the Dynamic RSI to ThinkOrSwim

The Dynamic RSI download installs as two separate studies:

Download the zip from this page. Inside are two study files, TI_DynamicRSI_LowerSTUDY.ts and TI_DynamicRSI_UpperSTUDY.ts, and Keith's Dynamic RSI Cheat Sheet as a PDF.
Import both .ts files as studies. Our guide on how to import a study into ThinkOrSwim walks through each click.
Add both studies to the same chart. The lower study opens in its own panel with the RSI, yellow average, bands, trend lines and red and green shading beyond 70 and 30. The upper study plots its arrows, bubbles and dots on the candles.
To build them by hand, click the Studies icon, choose Create, paste in the code from the Code tab and name the study. I used TI_DynamicRSI_Upper and TI_DynamicRSI_Lower.
Scroll to the right edge of the chart to see the trend lines. Each one covers only the most recent 150, 80 or 40 bars.

In the upper study every plot of Keith's code became a def, which is calculated but never drawn. ThinkOrSwim needs at least one plot in a study, so the error "at least one plot should be defined" showed up in the video until the arrows went in.

Dynamic RSI Settings

The Dynamic RSI has the same inputs in both studies, plus 3 trend line lengths in the lower study. These are the defaults in the download:

Input	Default	What it does
length	14	Bars in the RSI line. The arrows read this RSI too.
over_Bought / over_Sold	70 / 30	Levels for the Enter and Exit bubbles and the lower panel's lines and RSI colors.
price / averageType	close / WILDERS	The price the RSI line reads and the average inside it.
showBreakoutSignals	no	Lower study: yes shows arrows when the RSI crosses back above 30 or below 70.
Volatility_Band	14	Bars in the yellow average and the bands. A comment in the code suggests 20 to 40.
STDEV_Multiplier	2	Standard deviations between the yellow average and each band.
RSI_Period	14	Length of the RSI the yellow average and bands are built from. A comment suggests 8 to 25.
RSI_Price / RSI_Price_Line	0 / 2	Left over from Keith's code. No plot uses them.
TrendLineLength1 / 2 / 3	150 / 80 / 40	Lower study: bars behind the long, medium and short trend lines.

The plotted RSI uses length and the bands use RSI_Period. Both default to 14, so they describe the same RSI. If you change one, change the other, or the RSI will be measured against bands built from a different RSI.

How the Dynamic RSI Code Works

The Dynamic RSI code starts from Keith's copy of the RSI and adds one block for each relationship. Here is each piece, with the reasoning from the video.