For risk management purpose,
Moomoo SG will recalculate your required margin in accordance with the margin requirement after the exercise of your in-the-money (or close to in-the-money) options. This action shall be performed on the day of expiry prior to the market close with no fixed schedule. Please note that Moomoo SG has the right to close such options position without further notice if a margin call is triggered during above period.