Working with Percent Change Charts
When you first create a chart, the y-axis commonly represents the price of the symbol's price range. Percent change charts use the y-axis to represent the percentage of price movement rather than price. Percent change charts display negative as well as positive percent change values. A positive value indicates an increase in the symbol's price from a specified bar and this increase is shown as a positive percent change on the y-axis. Conversely, a negative value indicates a decrease in the symbol's price from a specified bar and this decrease is shown as a negative percent change on the y-axis. A horizontal zero line divides positive and negative percent values and allows you to clearly view if a percent change value is positive or negative.
Percent change is calculated from a specific bar, known as the anchor bar. Percent change is calculated by subtracting the close of each bar from the close of the anchor bar and then dividing this value by the close of the anchor bar.
The following is an example of how a price bar on a percent change chart is calculated. If the anchor bar has a price of $10.00 and the last bar included in the percent change calculation is $12.00, the percent of change would equal 20% on the last bar. The last bar's y-axis value would be 20%, representing the 20% price increase above the anchor bar.
Percent change charts are particularly useful when comparing price movements of multiple symbols because percent change charts allow you to compare different symbols on the basis of price percent changes rather than on price alone. Another benefit of percent change charts is the ability to compare the rate of return from a specific bar (for example, from last bar, first bar, this bar) and any other bar.
When the percent change feature is enabled in a chart, all data streams are moved into a subgraph of Data1 and are displayed as line on close unless you disabled the Auto select feature.
Related Topics
Converting a Chart to a Percent Change Chart