Search results
Results from the WOW.Com Content Network
In Fama's influential 1970 review paper, he categorized empirical tests of efficiency into "weak-form", "semi-strong-form", and "strong-form" tests. [2] These categories of tests refer to the information set used in the statement "prices reflect all available information." Weak-form tests study the information contained in historical prices.
In the 1970s Eugene Fama defined an efficient financial market as "one in which prices always fully reflect available information". [3] Fama identified three levels of market efficiency: 1. Weak-form efficiency. Prices of the securities instantly and fully reflect all information of the past prices. This means future price movements cannot be ...
In weak form efficiency the information set is just historical prices, which can be predicted from historical price trend; thus, it is impossible to profit from it. Semi-strong form requires that all public information is reflected in prices already, such as companies' announcements or annual earnings figures.
Either way, I think it's a bad idea to time the markets and conclude that 2025 will be a weak year just because 2023 and 2024 were some of the best years we've had in recent memory.
The random walk hypothesis may be derived from the weak-form efficient markets hypothesis, which is based on the assumption that market participants take full account of any information contained in past price movements (but not necessarily other public information).
Weak Pareto efficiency is a situation that cannot be strictly improved for every individual. [ 12 ] Formally, a strong Pareto improvement is defined as a situation in which all agents are strictly better-off (in contrast to just "Pareto improvement", which requires that one agent is strictly better-off and the other agents are at least as good).
Weak form and strong form may refer to: Weaker and stronger versions of a hypothesis, theorem or physical law; Weak formulations and strong formulations of differential equations in mathematics; Differing pronunciations of words depending on emphasis; see Weak and strong forms in English; Weak and strong pronouns
Rather, as the article goes on to make clear, EMH puts forth several different sets of conditions, "strong form", "semi-strong-form", and "weak form" efficiency. The extent to which a pricing market follows one of these forms, (or none of them, for that matter) one can use prices to infer information. --Thesurveyor 01:03, 3 July 2007 (UTC)