If you have no free margin, you will not be able to open any new positions and/or your positions will be stopped out. Your account balance can reach zero should the loss on the positions stopped out meet, or exceed, your account balance.
CFDs are complex instruments and come with a high risk of losing money rapidly due to leverage. 76.09% of retail investor accounts lose money when trading CFDs with this provider. You should consider whether you understand how CFDs work and whether you can afford to take the high risk of losing your money.
If you have no free margin, you will not be able to open any new positions and/or your positions will be stopped out. Your account balance can reach zero should the loss on the positions stopped out meet, or exceed, your account balance.