Stop Loss Order
Stop loss orders make sense when you cannot access your account. The intent is to limit a loss at a certain price or percentage. The problem is that stop loss orders are easily detected by unscrupulous entities. An alternative is Price Alerts.
These days you can set-up price alerts that will notify you by email and/or text. Once you receive the price alert you can access your account and execute the order.
Keep in mind, however, that a Stop Loss Order is similar to a set-it and forget-it concept whereas a Price Alert will require you to take action (execute the order). You must remove emotions and stick with your trading plan. Think of it this way: you set-up the Price Alert to take an action, therefore once the Price Alert is received you shall complete that action.