The Treaty of Versailles imposed a huge debt on Germany that could be paid only in gold or foreign currency. With its gold depleted, the German government attempted to buy foreign currency with German currency,[9] equivalent to selling German currency in exchange for payment in foreign currency, but the resulting increase in the supply of German marks on the market caused the German mark to fall rapidly in value, which greatly increased the number of marks needed to buy more foreign currency.

https://en.wikipedia.org/wiki/Hyperinflation_in_the_Weimar_R...