Time Axis Settings are common for all chartings, they include chart aggregation, expansion, and display parameters.
To customize the settings:
1. Make sure the Chart Settings window is open. For information on accessing this window, refer to the Preparation Steps article.
2. Choose the Time axis tab. This area allows you to define parameters of the time axis.
Chart Aggregation
This area allows you to set the desirable aggregation type.
1. Choose "Time" from the Aggregation type dropdown list to enable time aggregation. Choose the desirable Time interval for which the price plot will be displayed. Aggregation period defines the period to collect price data for one bar. Abbreviations: WTD stands for "week to date", YTD is "year to date", and Opt Exp means that the period between two consecutive expiration Fridays is taken to aggregate data for one bar.
You can also use a custom time interval; to do so, choose Custom from the dropdown. in the controls that appear afterward you can specify a certain time period in the past (if there is available price data for that period) or a number of years/months/days up to today. Specifying the latter will display all the available chart data for the period and when the current day is over, the chart will keep updating and the left-hand chart limit will be pushed forward one day.
2. Choose "Tick" from the Aggregation type dropdown list to enable tick aggregation. Choose the desirable Time interval for which the price plot will be displayed. Aggregation period defines the number of trades corresponding to a single bar. You can specify any number from 1 through 10,000 by typing it or moving the slider below.
3. Choose "Range" from the Aggregation type dropdown list to enable range aggregation; two modes of range aggregation are available in thinkorswim: Range Bars and Renko Bars. Choose the desirable time interval for which the price plot will be displayed. Set the price range (in tick sizes) to be accumulated for a single bar: specify a custom value or choose a predefined one from the drop-down list. On that list, ATR stands for Average True Range. Choosing this option will produce a chart with aggregation equal to arithmetical mean of True Range calculated for the whole chart.
4. Select Keep time zoom if you prefer to keep the defined time axis scaling after such chart manipulations as detaching chart window, changing symbol, adding or removing studies, and changing time frame. If Keep time zoom is not selected, the default scaling will be applied.
Expansion
1. The Expansion area field allows you to specify the number of bars to enlarge the subgraph space to the right. Note that the maximum expansion is 1000 bars.
2. Autoexpand to fit. This section allows automatic expansion of the time axis if chart elements suggest some future activity.
- Select Corporate actions if you prefer to expand the time axis so that future corporate actions are displayed on chart.
- Select Options to expand the subgraph space and display listed options. Note that this will only work if Show options is selected on Equities or Futures tabs.
- Select Studies to automatically set subgraph expansion so that studies such as Ichimoku, Profile, and Probability of Expiration Cone are plotted completely.
Note that expansion settings can be also reached by pressing the Right expansion settings button in the bottom right corner of the chart.
Display
1. Show rollover lines. Select this option to highlight the end of the trading day with a vertical "rollover line".
2. Show expiration Friday. Select this option to highlight expiration Fridays with a red dotted line. Expiration Friday is the third Friday of the month, the day when American style options expire.
3. Show year marking lines. Select this option to display a line separating the last bar of the ending year from the first bar of the beginning year.