What needs to be taken into consideration when carrying out stock trading transactions?

You need to check the status of all your orders after you place them. Your Improvement, Correction and Cancellation transactions are  executed depending on the status of your orders.
You can place Improvement / Correction / Cancellation orders for all your orders with “On the Stock Exchange” status.
If there is an order from another brokerage house for the same stock that you placed a correction order for, your correction order is not executed. However if you have placed  an Order Improvement order, it will be executed.
For orders placed with market price, no Order Improvement and Order Splitting transactions can be executed.