This article explains what appeared to be a paradox. On April 27, the European Central Bank raised its interest rates by 0.25%. Shortly after this announcement, the value of the Euro plummeted. The explanation of this phenomenon is that the Central Bank's reaction was not bold enough. Added to other instances of hesitant reactions it lead the market to believe that it does not have the will nor the strength to defend its currency.
AFTALION, F. (2000). Le prix des promesses non tenues. L'Hémicycle, pp. 11.