Until when can a market order be cancelled?
As long as a market order's status is not "executed", a cancellation request may be sent. Whether cancellation is still possible depends on the progress of the order execution.
Note: For technical reasons and depending on other factors, a cancellation request does not guarantee that the order is actually cancelled. As long as the order status is not "cancelled", the order is still considered to have been placed.
If you have any questions, please ask your client advisor.