Orders made outside market hours are queued and fulfilled either at or near the beginning of at or near market open, according to your instructions. These orders may be named as off market orders or overnight order.
That is the same as how you would place ordinary orders, except that the orders states are in the "waiting for submission".
Investors can place an order after the closing (15:00 Beijing time). The order is saved by Futu's trading system and automatically submitted to the exchange after the market open (09:30 Beijing time).
Note: Orders will be submitted to the exchange according to the order in which they were placed. Please wait patiently during the queuing process.