"It's a mess, it puts Angela Merkel in a hugely embarrassing position," Howard Wheeldon from BGC Partners told CNBC Wednesday after GM decided against selling its Opel Unit. Simon Grose-Hodge from LGT Bank in Liechtenstein joined the discussion.

"Even though we had good economic data yesterday, the stock market hit a real air pocket and judging from the futures, it seems like that's dragging us down," Rob Morgan, president of Dearden, Maguire, Weaver & Barrett, said Tuesday ahead of the US open. "We're in Fed meeting mode now, that tends to make the market tread water until that comes out," he added.

"We're giving back some of the gains that we had the last six months," Bernie McGinn from McGinn, McKean & O'Neill said Tuesday as to why stocks are down. "Everybody is going to be a long-term investor until it starts to get a little rough and I expect for the next couple of weeks, maybe even couple of months, we're going to have some pretty rough times."

"The event risk that we have this week is colossal. There's a lot of fear there," Marc Ostwald from Monument Securities said Tuesday. "With the amount of event risk that's there, it's understandable that quite a few people are anxious to book some profits as we go into year end."

The Australian Central Bank raised its key interest rate by 25 basis points for the second straight month Tuesday, as widely expected. Andrew Freris from BNP Paribas Wealth Management told CNBC the central bank would be unlikely to raise rates in December.

The UK construction sector is flat on its back and is likely to stay like that for some time, Peter Dixon from Commerzbank Securities told CNBC Tuesday. The outlook for the manufacturing sector is better, he said.

Investors are a little bit concerned about the prospect of central banks removing accommodative measures, Tim Condon from ING Financial Markets told CNBC Tuesday. David Karsbol from Saxo Bank joined the discussion.

Markets will be looking to the Fed meeting this week "more than anything else," Charles Lemonides, founder & CIO of ValueWorks, told CNBC Monday. There is concern that the Fed will start talking about the improving economy, and this could add a level of “nervousness" creating bumps in the market, he added.

The Nikkei 225 shed 2.3% to just more than 9,800 points Monday, following losses on Wall Street on Friday. The strength of the yen hurt major exporters such as Toyota, Cannon and Sony. Ken Moriyasu from the Nikkei has more.

“Where we are is pretty clear: the economy is definitely transitioning to a better place than it 6-9 months ago,” Charles Lemonides, founder & CIO of ValueWorks told CNBC Monday. The market has had a strong run giving us “some shakes and wiggles back and forth last week,” he said, adding that he “wouldn’t read too much into it.”

"What is happening in central and eastern Europe is what happens all over the world," Michael Buhl, CEO of Vienna Stock Exchange, said Monday. "The crisis is imported there because it is not something which has generally come from the central and eastern European countries. It comes from the simple fact that they heavily depend on direct financial investments from the West."

The Bank of England "probably won't expand" its quantitative easing program when it meets this week, Roger Nightingale from Pointon York said Monday. "It's very high indeed at the moment and there's the beginning of a reaction against quantitative easing."