When a stock gets delisted from its respective trading venue, trading with it gets suspended until additional information about the delisting is disclosed. When the official terms of the delisting are clarified, we execute the event on the platform in accordance with them.
In almost all cases, the shares of a delisted stock eventually get liquidated at a certain price or are deemed worthless at the price of 0.
In the context of US markets, sometimes stocks traded on NYSE or NASDAQ get downlisted from the main market to the OTC (Over-the-Counter) Markets. In such cases, we can allow trading with the stock on Invest and on ISA should the stock be eligible to be held there.