The European Central Bank (ECB) surprised many in the markets on Thursday by cutting its main interest rates to a record low of 0.25 percent in an attempt to help kickstart the euro zone economy.
But what's left in President Mario Draghi's arsenal if the bank needs to unleash further accommodative steps after this week's cut?
"We are doubtful that the ECB can still offer many of these big-bang days in the future," Carsten Brzeski, a senior economist at ING said in a research note on Thursday.
The policy move has increased the ECB's reputation as the euro zone's "pro-active firefighter", he said, but the cut will hit the ECB's predictability and make future forward guidance and market expectation management more complicated, he added.
(Read More: ECB rate cut joltsmarkets, but is it the fix?)
"On-going deleveraging in both the private and the public sector should exert further deflationary pressure which will be hard to tackle by monetary policy. Let's not forget that there have been more of these pulling-out-all-the-stops days at the ECB over the last years with cheerful reactions on financial markets but limited impact on the real economy."
Richard Kelly, senior global strategist at TD Securities, told CNBC that if the downside risks to growth are bad enough, then the ECB knows it will have to respond and Fed-style bond-buying programs -- know as quantitative easing (QE) -- could be the only option.
"They really don't have anything left, this was their one shot to weaken off the euro. After this it really is negative rates or QE," he said.
"(QE) really becomes the only option and you really would expect very loud volatility going around that."
As well as cutting its main interest rate by a quarter point, the ECB trimmed its emergency lending facility by 0.25 percentage points to 0.75 percent. It kept its deposit rate at zero. While speculation increased about a rate cut after a very low October inflation reading, many strategists had not expected the ECB to make a move until December.