Turnover fee can be set by a Trader in the Strategy settings. The turnover fee varies from 0 to 5 USD per lot. The fee is paid to the Trader immediately after a position is closed. Turnover fees are not paid on stocks.
For example, the Trader has set a turnover fee of 5 USD per lot for his Strategy. The Investor copied 0.6 lots of EUR/USD. When this position is closed, the Investor will be charged 0.6 * 5 USD = 3 USD.