A senior member of the European Central Bank warned on Tuesday that the current period of relative calm on the financial markets may be temporary.
Speaking at a financial conference in Frankfurt, ECB Executive Board member Benoit Coeure said: "We have seen a considerable improvement on financial markets since last summer (but) the period of calm ... may not last."
Coeure also reiterated that the central bank was prepared to put into action its programme of bond-buying for debt-wracked countries if they decide to apply for a European bailout.
Government bond markets and stocks have enjoyed a considerable bounce since July when ECB President Mario Draghi pledged to do "whatever it takes" to rescue the embattled single currency.
Since this pledge, Draghi has broken new monetary policy ground by promising to buy up the bonds of struggling countries if they first sign up to a bailout and strict conditions attached.
This programme, known as Outright Monetary Transactions or OMTs, has also calmed the markets although it has not yet been pressed into service.
Rumours that Spain is on the point of requesting such a bailout and therefore receiving ECB aid have circulated frequently in recent months but Madrid has so far hesitated to take the plunge.