David Lamb, senior dealer at the foreign exchange specialists FEXCO, comments:
"The first victim of the ECB's war on deflation was the Euro. The single currency duly hit the deck within seconds of Mario Draghi's announcement that he is finally pulling the QE trigger.
"While a fall in the Euro had been expected, the scale of the ECB's bond buying programme took the markets by surprise and sent the single currency plunging to a seven-year low against the Pound.
"But to say the decision to set the Eurozone's money presses rolling is too little too late is an understatement. It's telling that Mario Draghi felt the need to manage expectations, warning Eurozone governments that they must make structural reforms too.
"The ECB's money printing bazooka is no magic wand.
"While Eurozone stock markets have rallied at the news, the revelation that even now the ECB's governing council was split on the QE decision shows the challenges of providing a single monetary policy for 19 economies.
"While British exporters will be looking on nervously, for British tourists heading across the Channel the tumbling Euro is an unalloyed bonus - their holiday Pound will now go much further."