The percentage of an account / capital that you are prepared to place at risk during the trading. The order size calculation is based on the gap between the entry and stop order, the valuation of the instrument, the instrument / account currency pairs and the buying power. If this option is selected, the risk will remain the same but the order amount will vary. This method offers a reasonable order size setting when using a combination of equities and leveraged products (Forex, Futures, etc.).