In GTS and GTS Pro, we display a yellow warning triangle if you are about to place a trade in an instrument in a different currency than the currency of the account AND you have an account available in the same currency as the instrument you are trading – in the below image the selected instrument is Apple, which is trading in USD – but the selected account is in EUR:
In the above example Apple is selected, a physical share. The warnings are displayed also for other instruments, as in the below image where you can see 2 examples:
A EURUSD option is selected while a EUR account is selected BUT: a USD account is also available. FX Option premiums are expressed in the secondary currency, in this case USD, so it makes sense to trade this instrument on a USD account, if one is available.
A DAX CFD, which is denominated in EUR is selected on a USD account AND a EUR account is available – so the platform suggests considering trading the CFD on the EUR account: