I have searched long enough to start a cryptocurrency exchange website. Asking the experts, they said, it needs the high level of expertise team to handle the PHP website. But I have found the solution now.
Cryptocurrency exchange script is available online which is simple to implement and handle. I have tried this software and they are rendering authentic service in building cryptocurrency trading/exchange solution. I have mentioned contact details for the company below. Go ahead if you are interested. Note: Have a demo before starting!