I asked Interactive Brokers what happens if BABA gets delisted. The response is in the description. What does this all mean in simple terms?

If a stock stops trading the shares remain in the account until they either start trading again or until the shares are removed by the depository (DTC in the case of US securities). That could be a short time or a very long time. It is important to remember that as long as the halted shares are in the account they will have a current margin requirement. In addition, if you have a short stock position you may be charged short stock interest if applicable. Investor bulletins from the SEC and Finra are available at the following links:

-SEC Trading Suspension link: LINK../trading-stock-after-sec-trading-suspension-be-aware-risks

Nasdaq Trading Halts web page: LINK../trader.aspx

Finra bulletin When the Trading Stops—Part 1: Trading Halts: LINK../when-trading-stops-part-1

Finra bulletin When the Trading Stops—Part 2: Delays and Suspensions: LINK../when-trading-stops-part-2

Finra bulletin When Trading Stops: What You Need to Know About Halts, Suspensions and Other Interruptions: LINK../finra-issues-new-invstor-alert-when-trading-stops-what-you-need-know

Securities which have been delisted from a stock exchange often continue to trade on an OTC basis in electronic venues such a PINK or OTCBB. Delisting, therefore, does not preclude a security from actively trading and IBKR will continue to reflect such securities in accounts unless they are cancelled or removed from the depository or clearing agent. Clients will not have the ability to transmit an order for stocks no longer listed on one of our offered venues. Also note that IBKR reserves the right to restrict inbound transfers of delisted securities classified as Microcaps regardless of whether or not you hold an existing position in your account.

-See the Interactive Brokers Knowledge Base for details: LINK../2892

Clients holding a long position may request a Special Liquidation of such shares should they wish to remove the holding from their account(subject to review). Further information on this process may be found here. Please note, this option will not be available to short holders.