Correlation Meter Indicator
This simple script calculates the covariance and correlation coefficient between two markets using arrays.
Table of Contents
How It Works
It’s a simple indicator, but very useful for determining how correlated your preferred markets to trade are.
A correlation reading of +1.0 means the markets are perfectly positively correlated, a reading of -1.0 means they are perfectly negatively correlated.
If you’re not sure what correlation & covariance are then here are some useful definitions:
Covariance
Correlation Coefficient
For traders this can be useful for deciding how much risk to spread across two markets that have a high correlation, or how to hedge existing positions by trading a negatively correlated market.
For investors this can be useful for building a truly diversified portfolio.
If a market has a high positive correlation, the black line will stay above zero most of the time. If a market has a high negative correlation, the black line will stay below zero most of the time.
A market with no or little correlation will bounce between the two or hover around zero most of the time.
The example market above is comparing Apple’s weekly price action to the S&P500’s over the past 20 weeks. It has a high positive correlation as the black line is above zero most of the time.
Good luck with your trading!
Settings

Lookback:Â How many bars to perform the calculation on.
Source:Â Price source to calculate the correlation on.
Reference Market:Â The reference market to compare to the current market.
Video Lesson
Here’s a YouTube video I recorded which takes you step-by-step through each line of code:
Source Code
// This source code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/ // © ZenAndTheArtOfTrading / www.PineScriptMastery.com // This script calculates the covariance and correlation coefficient between two array data sets // @version=4 study("Correlation Meter", overlay=false) // Get user input lookback = input(title="Lookback", type=input.integer, defval=20) source = input(title="Source", type=input.source, defval=close) reference = input(title="Reference Market", type=input.string, defval="OANDA:SPX500USD") // Get % change of reference data source referenceData = security(symbol=reference, resolution=timeframe.period, expression=source) referenceChange = ((referenceData - referenceData[1]) / referenceData[1]) * 100 // Get % change of current market currentData = source currentChange = ((currentData - currentData[1]) / currentData[1]) * 100 // Declare arrays var referenceArray = array.new_float(lookback) var currentArray = array.new_float(lookback) // Shift (remove) the last (first entered) value from our arrays (FIFO) array.shift(referenceArray) array.shift(currentArray) // Add the current values to our arrays array.push(referenceArray, referenceChange) array.push(currentArray, currentChange) // Determine & plot our covariance relationship covariance = array.covariance(currentArray, referenceArray) plot(covariance, color=color.purple, style=plot.style_area, transp=0, display=display.none, title="Covariance") // Plot our reference data plot(referenceChange, color=color.red, style=plot.style_columns, transp=10, display=display.none, title="Reference Market") plot(currentChange, color=color.blue, style=plot.style_histogram, linewidth=4, display=display.none, title="Current Market") // Determine the standard deviation of our arrays referenceDev = array.stdev(referenceArray) currentDev = array.stdev(currentArray) correlation = covariance / (referenceDev * currentDev) plot(correlation, color=color.black, linewidth=2, style=plot.style_stepline, title="Correlation Strength") // Plot reference lines hline(price=1.0) hline(price=-1.0) hline(price=0.0)
Last Updated: 3rd March, 2021