efficient market hypothesis

简明释义

有效市场假设

英英释义

例句

1.Many investors believe in the efficient market hypothesis and avoid trying to time the market.

许多投资者相信有效市场假说，并避免试图把握市场时机。

2.Critics of the efficient market hypothesis argue that markets can be influenced by irrational behavior.

批评有效市场假说的人认为，市场可以受到非理性行为的影响。

3.The efficient market hypothesis has implications for both portfolio management and financial regulation.

有效市场假说对投资组合管理和金融监管都有影响。

4.According to the efficient market hypothesis, stock prices reflect all available information.

根据有效市场假说，股票价格反映了所有可用的信息。

5.The efficient market hypothesis suggests that it is impossible to consistently achieve higher returns than the average market return.

有效市场假说认为，不可能持续获得高于市场平均回报的收益。

作文

The concept of the efficient market hypothesis (EMH) is fundamental in the field of finance and investment. It posits that financial markets are 'informationally efficient,' meaning that asset prices reflect all available information at any given time. This theory was developed in the 1960s by economist Eugene Fama, who suggested that it is impossible to consistently achieve higher returns than average market returns on a risk-adjusted basis, since prices already incorporate and reflect all relevant information. To understand the efficient market hypothesis, it is essential to grasp its three forms: weak, semi-strong, and strong. The weak form asserts that past stock prices do not influence future prices, suggesting that technical analysis is ineffective. The semi-strong form claims that all publicly available information is reflected in stock prices, rendering fundamental analysis futile. Finally, the strong form states that even insider information cannot give an investor an advantage, as all information—public or private—is already accounted for in stock prices. The implications of the efficient market hypothesis are significant for investors. If markets are truly efficient, then attempting to outperform the market through stock picking or market timing would be a fruitless endeavor. This challenges the traditional view that skilled investors can identify undervalued stocks or predict market movements. Instead, proponents of EMH argue that a better strategy for most investors is to invest in low-cost index funds that track market performance rather than trying to beat the market.However, the efficient market hypothesis has faced considerable criticism. Critics argue that markets are not always efficient and that there are numerous instances of irrational behavior among investors that can lead to mispriced assets. Behavioral finance, which studies the psychological influences on investor behavior, provides evidence that people often act irrationally, driven by emotions and cognitive biases. For example, during market bubbles, investors may drive prices far above their intrinsic value, only for them to crash later when reality sets in. Additionally, there are anomalies such as the January effect, where stock prices tend to rise in January, contradicting the EMH. Other phenomena like momentum investing, where stocks that have performed well in the past continue to do so in the short term, also challenge the validity of the efficient market hypothesis. Despite these criticisms, the efficient market hypothesis remains a cornerstone of modern finance. It serves as a benchmark against which the performance of active management strategies can be measured. Many financial professionals still believe in the efficiency of markets to some extent, acknowledging that while markets may not be perfectly efficient, they are generally efficient enough that beating them consistently is exceptionally challenging. In conclusion, the efficient market hypothesis offers valuable insights into how financial markets operate. While it has its limitations and has been challenged by various theories and real-world evidence, understanding EMH is crucial for anyone involved in investing or financial analysis. Whether one agrees with its principles or not, the discussion surrounding the efficient market hypothesis continues to shape the landscape of investment strategies and financial theories.

有效市场假说（efficient market hypothesis，EMH）是金融和投资领域的一个基本概念。它认为金融市场是“信息有效的”，这意味着在任何给定时刻，资产价格反映了所有可用的信息。这个理论由经济学家尤金·法马（Eugene Fama）在20世纪60年代提出，他认为，由于价格已经包含并反映了所有相关信息，因此不可能在风险调整的基础上持续获得高于平均市场回报的收益。要理解efficient market hypothesis，必须掌握其三种形式：弱式、半强式和强式。弱式假说认为过去的股票价格不会影响未来价格，这表明技术分析是无效的。半强式假说声称所有公开可用的信息都反映在股票价格中，使得基本面分析无效。最后，强式假说指出，即使是内部信息也无法使投资者获得优势，因为所有信息——无论是公开的还是私人的——都已在股票价格中得到体现。efficient market hypothesis的含义对投资者具有重要意义。如果市场确实有效，那么通过选股或市场时机来超越市场将是一项徒劳的努力。这挑战了传统观点，即熟练的投资者可以识别被低估的股票或预测市场走势。相反，EMH的支持者认为，大多数投资者更好的策略是投资于跟踪市场表现的低成本指数基金，而不是试图超越市场。然而，efficient market hypothesis遭到了相当大的批评。批评者认为市场并不总是有效，并且存在许多投资者的非理性行为会导致资产定价错误。行为金融学研究投资者行为的心理影响，提供了人们常常非理性行事的证据，这些行为受到情感和认知偏差的驱动。例如，在市场泡沫期间，投资者可能会将价格推高到远超其内在价值的水平，等到现实回归时又会崩溃。此外，还有一些异常现象，如一月效应，股票价格在一月往往会上涨，这与EMH相矛盾。其他现象如动量投资，即过去表现良好的股票在短期内继续表现良好，也挑战了efficient market hypothesis的有效性。尽管存在这些批评，efficient market hypothesis仍然是现代金融的基石。它作为一个基准，用于衡量主动管理策略的表现。许多金融专业人士仍然在一定程度上相信市场的效率，承认虽然市场可能不是完全有效的，但通常足够有效，以至于持续战胜市场是极具挑战性的。总之，efficient market hypothesis为我们提供了关于金融市场运作的重要见解。尽管它有其局限性，并受到各种理论和现实证据的挑战，但理解EMH对于任何参与投资或金融分析的人来说都是至关重要的。无论一个人是否同意其原则，围绕efficient market hypothesis的讨论继续塑造投资策略和金融理论的格局。