Efficient Market Hypothesis (EMH) (EMH) Study Guide
The Efficient Market Hypothesis (EMH) holds that asset prices incorporate available information, making it difficult for investors to consistently outperform the broader market over the long term. It is better understood as a framework for analyzing how information is incorporated into prices than as a market law that has been fully proven.
Core Concept
The Efficient Market Hypothesis was proposed by economist Eugene Fama in the 20 century 60 decade. Its core view is that known information is rapidly incorporated into asset prices by market participants, bringing assets closer to fair value; if markets were perfectly efficient, investors would find it difficult to consistently outperform the overall market over the long term based on currently available information.
Forms of Efficiency
Weak form efficiency holds that prices already reflect historical price data; Semi-strong form efficiency further includes public information such as news and company announcements; Strong form efficiency holds that both public and private information are reflected in prices. The forms progressively broaden the scope of information while correspondingly narrowing the scope for investors to gain an informational advantage.
Implications for Analytical Methods
Under Weak form efficiency, technical analysis relying solely on historical prices is unlikely to consistently generate an advantage, though fundamental research may still be useful. Semi-strong form efficiency holds that public information has already been absorbed, making fundamental analysis unlikely to remain consistently effective. Strong form efficiency is the most stringent: even insiders with private information cannot consistently maintain an advantage.
Controversies and Crypto Markets
Empirical research has not fully confirmed or disproved this theory. Critics argue that sentiment and behavioral factors may cause assets to be overvalued or undervalued; the efficiency of crypto markets can also change significantly over time, and anomalies such as the day-of-the-week effect challenge strict market efficiency. Therefore,EMH should be regarded as a tool for thinking rather than a definitive conclusion.
Original Tutorial
https://www.binance.com/en/academy/glossary/efficient-market-hypothesis-emh