History of Switzerland
Switzerland's most important exports during the war were precision machine tools, watches, jewel bearings (used in bombsights), electricity, and dairy products. During World War Two, the Swiss franc was the only remaining major freely convertible currency in the world, and both the Allies and the Germans sold large amounts of gold to the Swiss National Bank. Between 1940 and 1945, the German Reichsbank sold 1.3 billion francs worth of gold to Swiss Banks in exchange for Swiss francs and other foreign currency.
Currency intervention
The Economist asserts that the SNB dropped the cap for the following reasons: first, rising criticisms among Swiss citizens regarding the large build-up of foreign reserves. Fears of runaway inflation underlie these criticisms, despite inflation of the franc being too low, according to the SNB. Second, in response to the European Central Bank's decision to initiate a quantitative easing program to combat euro deflation. The consequent devaluation of the euro would require the SNB to further devalue the franc had they decided to maintain the fixed exchange rate. Third, due to recent euro depreciation in 2014, the franc lost roughly 12% of its value against the USD and 10% against the rupee (exported goods and services to the U.S. and India account for roughly 20% Swiss exports).