TradOwise operates under the closed-loop policy.
When you are ready for a withdrawal, you need to cash out with the same method as you have made a deposit.
If you deposit $50 via Bitcoin(BTC) and make a profit of $50, now you have $100 on your account. It is a priority to withdraw back the initial deposit amount first. In that case, the minimum will be $50 before using any other withdrawal method for your profit.
You can also withdraw all of $100 altogether.