Why my pending order is cancelled on MT4? I didn't mean to cancel it.

With FBS, your pending order will be deleted from the system if free margin (Equity – Used Margin) is not enough to cover the margin required for opening the specific order.

So in case you have set some pending orders, then depending on the free margins in your trading account, they could be cancelled automatically if these orders cannot be placed due to the low free margin.

Pending orders to close positions such as Take Profit and Stop Loss, won’t be cancelled even if you have got low free margin.

But please note that on FBS MT4 and MT5, in case your margin level goes below 100%, stop out will be triggered and all your open positions will be closed automatically in order to avoid further losses in your trading account.

You pending order cancellation will be also made according to the 20% of margin level. Meaning that if the system calculates that en execution of pending orders will trigger stop out, then the pending orders will be cancelled automatically.

Fortunately just like many other brokers, FBS covers all exceeded losses in your trading accounts, so you will not lose more than you deposit.

But please note that a Stop-out can cause a full loss of your account funds in a moment.