More than 60 billion ($116 billion) was wiped off the value of Switzerland's leading companies after the central bank scrapped the cap on the Swiss franc against the euro.
The Swiss National Bank's decision to abandon the three-year ceiling sparked a near 30 per cent surge in the franc against the European currency - a sudden increase in volatility that in turn triggered a bout of equity market turbulence.
The Swiss Market Index fell the most in 25 years, with volumes seven times the normal 30-day average as traders scrambled to react to the shock move. The indices closed 8.7 per cent lower to 8400.61 - the lowest point since 1989.
Watchmaker Swatch Group collapsed by 16.4 per cent, prompting its chief executive Nick Hayek to make an impassioned statement that the decision to end the minimum exchange rate on the Swiss franc was a "tsunami" for the Alpine country.
"Words fail me," Hayek said. "SNB action is a tsunami, for the export industry and for tourism, and finally for the entire country."