Why can I not see option volume outside of regular trading hours?

Market data is provided free of charge during the US overnight trading session. 

Additional Information…

IBKR does not offer trading in stocks on the Irish Stock Exchange.

However, some stocks listed on the Irish Stock Exchange might be available for trading on other markets where you can trade with IBKR. For more information on the available exchanges, see the…

The Show data outside of regular trading hours item in the TWS Chart Parameters window is greyed out when no outside of regular trading hours session is available for the product in the chart.

You can check the trading hours for a product by right-clicking its ticker row in TWS, and selecting:…

Open Interest by Strike is not available in a graphical way for stocks from some regions of the world.

In case it is not available, when you click on Open Interest by Strike, it will load the Option Volume data instead…