You can trade expiring options up to the end of the last trade date if the account has sufficient funds to meet both the real time and projected margin requirements. The cut-off time for when you can open a new option position that expires the same day or the time you have left to close an open expiring option position depends on the available funds in the account. Starting 2 1/2 hours before trading ends on the contracts last trade date IB's Expiration Exposure monitoring can start closing positions if the account is projected to be in a margin deficit after expiration. Also when the "Post-Expiry Excess (predicted)" line in your Account Window has a negative balance you would not be allowed to open a position that would increase a projected post expiration margin deficit.
How late can I open a new option position on expiration day?
You may refer to the "Day Trades Left (T, T+1, ..., T+4)" counter on the Available for Trading…
Overview:
There are two scenarios which could occur if a long option is taken to expiration. If the option is out-of-the-money at expiration and you do not choose to exercise it, the option will expire worthless, and your losses will consist of the premium that was paid to acquire the option. If the option is in-the-money at expiration by 0.01 or more, it will be automatically exercised on your behalf (unless you previously chose to lapse the option) by the Options Clearing Corporation (OCC). The OCC processes monthly expiration options on the third Saturday of the month, or the day after Friday expiration. The resulting long or short position will be put into the account, effective on the Friday trade date. If the account has sufficient margin to satisfy the requirement on the resulting position, it will then be up to the account holder to decide what they want to do with the position. If the resulting position causes a margin deficit, the account will be subject to liquidation at a time which is defined by the holdings within the account. Please be aware that any positions could be liquidated as a result of the account being in margin violation—the liquidation is not confined to only the shares that resulted from the option position. For example, if the account holds currency, futures, future options positions or and non-USD product, the account may begin to liquidate to meet the margin deficit as soon as a corresponding market opens…
You can monitor your margin values in real time using your TWS/Mosaic Account Window by looking in the Margin Requirements and Available for Trading sections. In the IBKR Mobile open the Account screen and…
The only action one can take to prevent being assigned on a short option position is to buy back in the option prior to the close of trade on its last trading day (for equity options this is usually the Friday preceding the expiration date although there may also be weekly expiring options for certain classes). When you sell an option, you provided the purchaser with the right to exercise which they generally will do if the option is in-the-money at expiration…