If you close the spreadsheet with the TradeSystem running and a value is in a cell that previously sent in an order (the “When”). Then, say you open the spreadsheet.
Because the TradeSystem is running and the “When” is a non-zero value an order will be sent in to the exchange. To avoid this, consider using a colored alert in the cells.
Below, if the TradeSystem (Cell C6) is <>0,then the cell is highlighted in red. You can apply this same color condition alert to other cells as a reminder to set them to 0 before closing the spreadsheet.