Yes, transferring your existing portfolio to BUX Zero is possible*. If you would like to make use of that service, please reach out to our support team via the in-app chat or send an email to firstname.lastname@example.org.
We do not offer the service to transfer your portfolio away from BUX Zero to another broker at this point.
*There are certain assets that cannot yet be transferred to your BUX portfolio, for example, German stocks. We're currently working on making this possible.