For over three years, the Swiss National Bank had maintained a cap on the Swiss franc's value against the euro, set at 1.20 francs per euro. This policy was introduced in response to the European debt crisis to prevent the Swiss currency from becoming too strong and harming the competitive position of Swiss exporters. However, as the eurozone's economic situation remained precarious, the SNB found itself under increasing pressure to defend the cap, leading to a significant buildup of foreign currency reserves.

On January 15, 2015, the SNB shocked the markets by announcing the abandonment of this cap. The decision was unexpected as it had been considered a cornerstone of the SNB's policy framework for several years. Consequently, the Swiss franc surged against the euro by as much as 30% within minutes, causing severe disruptions in forex markets and prompting many brokers to incur large losses. The sudden appreciation led to a wave of panic selling across European markets, highlighting the interconnectedness of global financial systems.

In the days following the announcement, a significant re-evaluation of currency positions took place, impacting not only individual traders and financial institutions but also broader economic indicators. The move by the SNB was interpreted as a signal of its dissatisfaction with the monetary policies of the European Central Bank (ECB), as the latter prepared for its quantitative easing program. Ultimately, the decision illustrated the volatility inherent in monetary policy and its far-reaching implications for investors and economies worldwide.