Stocks in both the Europe and the US market soared after the ECB announced a larger-than-expected bond-buying program.
But some analysts express worries that the program may help only temporarily.
Robert Halver is head of market research Baader Bank from Germany.
"Mr (Mario) Draghi did not disappoint the markets. He made it clear that he wants to get the inflation rate up to two per cent whatever it takes. Should this not work until September 2016 when this programme is supposed to end, it will be extended. "
However, few options were left for the ECB to choose in terms of fighting the risk of deflation.
The annual inflation rate in the euro zone dipped into negative territory and reached minus 0.2 percent despite the ECB's previous stimulus efforts.
Meanwhile economists here in China also warn that the QE policy might also serve as a double-edged sword for Chinese economy.
Guan Tao is head of the department of international payments at the State Administration of Foreign Exchange.
"On one hand, given the monetary policy of the U.S. getting normalized, European QE would ease the tightening effect of the withdrawal of the U.S. QE. On another hand, the widening division of the monetary policies of the major world economies will affect exchange rates among major currencies, which will further jolt the international finance, particularly the foreign exchange market. It will also make it more difficult to manage cross-border capital flow and currency expectation."
From March of this year, the ECB and national central banks in the euro zone purchased additional bonds and securities from euro zone governments, agencies, and European institutions amounting to about 69 billion U.S. dollars per month.
