A technical stock analyst named John Bollinger developed the technique and trademarked the name. If you understand how to compute moving average and standard deviation, you can make a Bollinger Band.
I used the stock price history web data connector to pull the daily closing prices going back to You can use this connector to analyze a wide variety of stocks simply by editing the connection, entering a different stock or index and updating the data source.
The dashboard information will change to reflect the new data source selected. The chart at the bottom of the dashboard shows the daily trading volume. I decided to parameterize the number of days used to compute the moving average and provided another parameter to allow you to change the number of standard deviations used for computing the Bollinger Bands.
The parameter control on the left will be used to determine how many days will be used in the table calculation for computing the moving average. The parameter control shown on the right allows you to change the number of standard deviations used to compute the Bollinger Bands.
To create the moving average line, right-click on the AVG Close field pill on the Row shelf and select Create table calculation. Just select the moving average option and pick 20 days.
Drag the close field from the Data pane into the Row shelf again to plot the average daily close amount, then make a dual axis chart with the left axis plotting the AVG Close value and the right axis plotting the moving average. You should now have circles being plotted from the left axis that shows the average daily closing price. From the right axis, you will have a line that is plotting the day moving average.
I suggest you control-drag the table calculation pill for the moving average to the Measures shelf and name the field Moving Average Close. The parameter should now be operating that controls the number of days to use for the moving average calculation. Next create the Bollinger Band - Lower field by making a calculated value that looks like the image below:.
The formula utilizes the moving average calculated earlier along with the parameter controls that enable you to change the number of standard deviations plotted from the average closing price and the number of days to use for the moving average calculation. Once you have the lower Bollinger Band created, duplicate the field and edit it to create the upper Bollinger Band by adding the standard deviation to the moving average instead of deducting it, then add both of the fields to the right axis with the Moving Average Close field.
Edit the color of the lines and the circle marks to your taste. I decided to stylize my tooltips after placing the Bollinger Band trading volume charts into a dashboard. This action highlights the chart marks by selecting marks in either chart. Bollinger Bands may help you determine when to buy or sell a particular stock, index mutual fund or ETF.
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