One of the easy ways to see how a country is performing relative to other countries is to look at its market cap as a percentage of world market cap.  In the early stages of the global rebound off of the March lows, the US rose significantly, but other countries were gaining even more.  In recent months, however, the tide has turned, and the US is now outperforming the rest of the world.  As shown below, US stock market cap as a percentage of world market cap has been steadily rising since last November.  During the 2003-2007 bull market, emerging markets and other countries really outperformed the US.  If this bull market continues and the US continues to gain share, it will represent a very big trend change that will make a huge impact on portfolio performance depending on an investor's domestic versus international equity allocation.

While the US is gaining share, China is losing share.  Aside from an uptick in the summer months of 2009, China's stock market cap as a % of world market cap has been trending downward throughout the entire rebound.