When your Sparkasse starts offering Bitcoin in October, you will not be buying coins that you then move to a wallet of your own. You receive a position in your securities account, and the cryptographic keys behind it stay with the bank. That is the central difference between what a high-street bank offers and an account at a crypto exchange, and it decides what you can actually do with your holdings later on.

This article takes on exactly that point. It explains what custody in a bank account means in practice and in law, which obligations an authorised custodian has to meet under the EU regulation MiCAR, which three public registers let you look up who really holds your crypto-assets, and which questions you should settle before your…