How do they charge commissions?

https://eu.swissmarkets.com/    

Swiss Markets is owned and operated by BDSwiss Group, a group with subsidies authorized and regulated by different regulatory bodies, including：

BDS Markets is authorised and regulated as a Investment Dealer by the Mauritius Financial Services Commission (Mauritius FSC) with license No. C116016172;

BDSwiss Holding Ltd is licensed by the Cyprus Securities and Exchange Commission (CySEC) under license number: 199/13.

As for the question you asked, we recommend that you ask the official customer services directly for a more accurate answer. Fore more details on this broker you can check our full Swiss Markets review.