This chart just ran in a "Chart of Day" article on Bloomberg Terminal. I can't link the article as it is not accessible on the Bloomberg website. The gist of the article is that compared to other rally's, the EM rally may be in its infancy with significant additional upside.
I hate these kinds of articles. What are they saying? They are saying the following: your gut tells you that current EM valuations have climbed unrealistically through the stratosphere, they are emerging markets with emerging markets type of political, legal, regulatory, social and economic risk which no one wants to discount anymore, the world financial system is in trouble, global GDP is just about turn the corner from its worst year in recorded history with no evidence of real economic momentum in the developed world, the drivers of world demand. But, hey, when you overly this one graph over these other crazy bubbles we had, it looks as if we can get a lot crazier before everyone looses their shirts.
I believe in the EM story. There probably is still a lot of upside. However, the reason is not because people went even crazier in other bubbles.
