Transferring crypto ETNs to a new broker in Germany: the loss pot only moves on request

A securities account transfer of crypto ETNs costs you no tax in Germany as long as you own the securities both before and after. The transferring bank must pass your acquisition data on to the new bank, by law and without you applying for anything. The move becomes expensive in two other places: your loss offset pot only comes along if you explicitly request it and transfer the entire account, and if the acquisition data get lost on the way, the new bank treats a flat 30 percent of the sale price as gain.