Germany’s Sparkassen savings-bank network and its cooperative banking sector are preparing to let ordinary customers buy and sell Bitcoin and Ether inside the same mobile apps they already use to check a current account. The Sparkassen group alone serves roughly 50 million retail clients, and the cooperative banks add another 30 million, which puts crypto access on a rail that reaches about 80 million customer relationships in a country of 84 million people, according to reporting on the combined rollout. Two years ago the savings-bank association labeled digital assets highly speculative and refused to touch them. That position has now reversed completely.

The shift matters because it changes who touches crypto and how. Instead of…