I note that unlike Efficient Markets Hypothesis, ..

"One of the reasons for this state of affairs is the fact that the Efficient Markets Hypothesis, by itself, is not a well-defined and empirically refutable hypothesis. To make it operational, one must specify additional structure, e.g., investor’ preferences, information structure, business conditions, etc. But then a test of the Efficient Markets Hypothesis becomes a test of several auxiliary hypotheses as well, and a rejection of such a joint hypothesis tells us little about which aspect of the joint hypothesis is inconsistent with the data. Are stock prices too volatile because markets are inefficient, or is it due to risk aversion, or dividend smoothing? All three inferences are consistent with the data. Moreover, new statistical tests designed to distinguish among them will no doubt require auxiliary hypotheses of their own which, in turn, may be questioned."
Lo and MacKinlay (1999), pages 6-7

Efficient-market hypothesis - Wikipedia

Most empirical tests indicate that the market is very close to being weak form efficient.
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Efficient Markets vs. CAPM | Seeking Alpha

Assesses the idea of efficient financial markets. It evaluates the theoretical and empirical foundations of the efficient markets hypothesis, emphasising the cracks that have emerged in them. Special attention is given to the rationality of investors, the randomness of the trades, and the role of arbitrageurs. Then the author suggests that an alternative theory—behavioural finance—could be more successful in explaining the evidence. The chapter concludes with a brief outline of the structure of the book.

09/08/2016 · Efficient Market Hypothesis ..

An efficient market implies that the stock price would increase immediately when the information is available -- not a year from now when the technology is implemented or even later when extra profits are received.

Empirical research shows evidence that the market is not strong form efficient.
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CFA Level 1 - The Efficient Market Hypothesis

A more moderate form of this type of market efficiency states that an abnormal return could be earned to the extent of fairly compensating the most efficient analyst for the effort spent accurately analyzing stocks to determine true mispricing.

Efficient Markets Hypothesis: Joint Hypothesis

For example, if you can look at historical prices (or price patterns) and determine those stocks which will give you higher than normal returns (which means they are currently underpriced), then the market is not weak form efficient.

efficient market hypothesis | Stephen Smith's Blog

"First, any test of efficiency must assume an equilibrium model that defines normal security returns. If efficiency is rejected, this could be because the market is truly inefficient or because an incorrect equilibrium model has been assumed. This joint hypothesis problem means that market efficiency as such can never be rejected."
Campbell, Lo and MacKinlay (1997), page 24

Efficient-Market Hypothesis Research

"For the CAPM or the multifactor APT to be true, markets must be efficient."
"Asset-pricing models need the EMT. However, the notion of an efficient market is not affected by whether any particular asset-pricing theory is true. If investors preferred stocks with a high unsystematic risk, that would be fine: as long as all information was immediately reflected in prices, the EMT theory would be true."
Lofthouse (2001), page 91