Or is it?
Well, perhaps there is some validity here but overall I would say the EMH is utter garbage - it is perhaps a wonderful Academic Exercise (and regular Readers will be aware most likely of how much I see little use for such Trash and I only respect such Theories if I have seen them to be true in my immersed experience of Markets over many years) but in truth it probably would only apply to a ‘Perfect’ Market where all Information available at a Point in Time is known to all the Participants in that Market and they react rationally and with 100% accuracy in an instant. I guess the flaws here are rather obvious apart from the simple fact that in The Real World (ah, the WD strapline !!) there is no such thing as a Perfect Market. It is a theoretical construct to help explain how Economies and Markets work but it is of little value to us as Investors (or Traders).