5 000 000 000 Mark

Lörrach sits on the Rhine directly opposite Basel, and in late 1923 that geography mattered enormously. Swiss francs were crossing the border in both directions as local residents desperately sought hard currency, while municipal authorities scrambled to print emergency Notgeld in denominations that would have been unimaginable two years earlier. Five billion marks was not an abstraction — it was roughly the cost of a loaf of bread during the peak hyperinflationary weeks of October and November 1923.

The official stamp is the sole security feature, which tells you everything about how quickly these notes were produced and how briefly anyone expected them to circulate.