In terms of the number of subscriptions, the Shanghai and Shenzhen Stock Exchanges clearly stipulate that the subscription of funds follows the principle of "once declared, the order cannot be withdrawn". Each securities account can only be subscribed once, and multiple subscription instructions of the same securities account are considered invalid except for the first subscription.
Use funds to participate in the subscription of new shares. If you win the lottery, you will buy the shares that will be listed soon. This is called playing new shares. Only institutions can buy offline, and you can buy online.