Yes, you can set it after logging into MT4.
1. In MT4, open 'Tools' –> 'Options' and click on the 'Server' tab
2. Click "Change Password"
3. Enter your MT4 login password in the "Current password:".
4. Select Investor(read-only) password
5. Enter the password you want to set and "New password" and "Confirm" fields, then click ok.
