Range charts represent price action in terms of price accumulation. Two modes of range aggregation are available in Charts: Range Bars and Renko Bars. You can set up range aggregation when selecting a time frame for your chart. Setting up the chart time frame is discussed in the next article. The mode of the range aggregation can be selected on the Time axis tab of the Chart Settings dialog.
1. Range Bars
In the Range Bars mode, a new bar (or candlestick, line section, etc.) is plotted after a specified price range has been accumulated. Each new bar opens at the previous bar's close price, which coincides with either high or low of that same bar, depending on its direction. You can use the following chart types with this aggregation mode: Bar, Candle, Candle trend, Heikin Ashi, Line, or Area. Range Bars are used by default when you enable range aggregation.
2. Renko Bars
Renko Bars are plotted as "bricks". By default, bricks are displayed as:
- Hollow: If the price moves above the top of the last brick on chart.
- Filled: If the price moves below the last brick on chart.
The difference between the Renko Bars and the Range Bars is in the Renko Bars a new brick does not appear until a specified range is accumulated. For example, on a five-point chart, the price rising from 95 to 102 produces a hollow brick from 95 to 100, however, a hollow brick ranging from 100 to 105 is not drawn. The only exception to the above example is the last bar on the chart; it always indicates the most recent price changes and is shown as incomplete until the necessary range is accumulated. Note that you can only use the Candle chart type with this aggregation mode. The price action is always displayed as bricks, i.e., candles without wicks (shadows).
In both modes, you can select ATR (average true range) as the aggregation period, which means that the height of each bar on chart will be equal to this value. As average true range is based on actual symbol price data, using it as the aggregation period produces the optimal quantity of bars.
Please note that based on the time interval and the price range set as the aggregation period, range charts may have the following data limitations:
- You can view up to 40,000 bars on a single chart. If the price range is too small, the chart time interval may not be available in full. In this case, consider increasing the price range.
- For longer chart time intervals, the older the data is, the less precise the visualization could be:
Range bars and volume bars for the last seven astronomical days (current day included) are created based on tick-level data.
Range bars and volume bars that are 7 to 14 astronomical days old are created based on 1-minute aggregates.
Range bars and volume bars that are 14 to 194 astronomical days old are created based on 1-hour aggregates.
Range bars and volume bars that are older than 194 astronomical days are created based on daily aggregates.
Range bars based on 1-minute, 1-hour, or daily aggregates are built in the following order:
high or low price (whichever is closer to open)
high or low price (whichever is farther from open)
Volume bars that are created from 1-minute, 1-hour, or daily aggregates use the following calculation algorithm. If there is an aggregate with a range that can accommodate several range bars, the volume of that bar is distributed evenly among all the range bars based on it.
- If ATR is selected as the aggregation period, the bars from today are excluded from the calculation and midnight Central Standard Time (CST) is used to demarcate today's bars from yesterday's bars. In addition, ATR calculation is adjusted based on the chart time interval you are currently using:
If the time interval is less than or equal to nine days, ATR is calculated over seven last astronomical days based on one-minute price aggregates.
If the time interval is less than or equal to 150 days, ATR is calculated over 7 last astronomical days based on 1-hour price aggregates.
If the time interval is greater than 150 days, ATR is calculated over the last 14 astronomical days based on 1-day price aggregates.