There are two action buttons in Chart Trader, the REV button and the CLOSE button.
The REV button stands for "reverse." When pressed, it will reverse your open position by closing out the open position and entering into the opposite position maintaining your ATM Strategy if one is applied.
Left mouse clicking on the CLOSE button will close the current position and cancel any working orders associated to the instrument/account combination. Clicking on this button with your middle mouse button (scroll wheel) will close the selected active ATM strategy only. This means that the position size of the strategy will be closed and any working orders associated to that strategy will be cancelled.