This post shows the various stock market indexes from around the world. Each continent of the earth is represented. This is just a sampling. I could have posted the stock market charts for Russia, China, India, Brazil, Canada, UK, France, Germany, South Africa, the United States, or just about any other country around the world. They would all look about the same. I have removed the symbols for the charts. See if you can guess what country's stock market index they represent. It wouldn't really matter much, because they all look about the same.
The point of these charts is simply to make the point that regardless of which stock market is chosen, they are so similar that it wouldn't matter which stock market index a trader chooses to trade, the results would be the same.
Decoupling is bunk, pure and simple!