CURRENCIES don't tend to move 7-8% in one day in the modern era but the Swiss National Bank has achieved the feat today. It announced a "minimum" exchange rate target of 1.20 francs per euro (here is the announcement) and the markets fell into line. In reality, the target rate is a ceiling, not a floor; if you turn the cross-rate round, the Swiss want the franc to be worth no more than 83.33 euro