Is it possible to have an option open interest indicator in a chart of TWS?

To make a chart the default in TWS:

1. Click the File menu within the chart that you want to save as a default
2. Select Save Chart Template As...…

You can set chart parameters when you open a chart, and modify parameters from within a chart using the Edit menu:

1. Click the Edit menu within the chart window followed by Chart Parameters.
2. Place a check-mark next to Adjust for dividends…

To add or remove news from a TWS chart, click on the Edit menu followed by Chart Parameters. In the Chart Parameters window, check or uncheck the box next to "News" within the "Highlight on chart" area. Click Apply and OK to save your changes.

Find out more about configuring charts in the …

To add an index for comparison to a TWS chart:

1. Click the Edit menu on top of your TWS chart.
2. Select Index Comparisons…