Brokers can be divided into three groups - classic banks, direct banks (banks without branches) and neo-brokers (trading applications). Classic banks and direct banks charge a minimum of 5-10 € per transaction, which is too expensive and greatly affects your profitability. Neo-brokers have significantly reduced the cost of trading. But neo-brokers also have their drawbacks - for example, they trade through exchanges, where there is not much variety of stocks. Since I recommend investing in funds, the portfolio of neo-brokers will be enough for you.