Silence Before Currency Revalues. Why?
To make a long story short, global currency revalues and devalues occur without warning. Here’s why:

A historical currency revaluation in 2015, the Swiss Franc revaluation. On January 15, 2015, the Swiss National Bank got rid of the peg with the Euro. The pegged exchange rate was 1.20 Swiss francs to a one Euro and was abandoned. As a result, the value of the Swiss Franc increased by 30%.