Down ...

Economists, historians and your stock broker will all tell you that China's stock market should not have a profound impact on your stocks. The key word here is "should," and this advice may no longer be true.

On Jan. 4, the Shanghai Composite index dropped 7%, forcing Chinese authorities to halt trading in stocks. The selloff sparked selling in markets around the globe, and the Dow Jones Industrial Average sank as much as 450 points that day. 

The prospect of a significant slowdown in China has serious repercussions for other emerging-market nations.

Obviously, Beijing is aware that it faces some big economic and financial challenges. China's leaders are under pressure to keep their economy going, and the obvious motivation for devaluation is to make exports cheaper. But a weaker yuan could lead to a flow of capital out of China, which would causes the value of the yuan to fall further. 

Would the china market take the world economy all together down? May be 2019 is the year for it.