50 Zlotys – Poland

In early 1990, Poland stood at a critical juncture, embarking on a radical economic transformation known as the "Balcerowicz Plan" or "Shock Therapy." The legacy of the communist era was a disastrous monetary situation characterized by hyperinflation, which peaked at over 600% in 1990, severe shortages, a worthless złoty, and a vast monetary overhang where large amounts of savings chased virtually no goods in the state-controlled market. The economy was isolated, with an inconvertible currency and multiple artificial exchange rates, crippling any chance of normal trade or investment.

The core of the January 1, 1990, reforms directly targeted this currency chaos. The złoty was made internally convertible, meaning Polish citizens and firms could freely exchange it for foreign currencies at a unified, fixed, and drastically devalued official rate set by the National Bank of Poland. This single, bold move aimed to stabilize the currency, kill the black market, anchor expectations, and open the economy to international competition. It was accompanied by strict anti-inflation policies: slashing subsidies, liberalizing most prices, and imposing severe credit restrictions.

The immediate results were harsh but structurally transformative. The fixed exchange rate acted as a crucial nominal anchor, helping to rapidly curb hyperinflation. While it led to a deep initial recession and a painful drop in living standards, it successfully established the złoty as a stable unit of account for the first time in decades. This painful yet decisive currency stabilization laid the essential groundwork for Poland's subsequent market economy, attracting foreign investment and setting the stage for future growth and, ultimately, integration into the European Union and adoption of the euro roadmap.