Efficient Market Hypothersis

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While the extent of the validity of these criticisms remains debated, the efficient-market hypothesis (EMH) has held a pronounced influence on political and academic thought. This essay considers the extent that the market, as Warren Buffet claims, functions under irrational processes, or can be explained in rational terms through the efficient market hypothesis. Outline of the Efficient Market Hypothesis (EMH) In its modern incarnation Professor Eugene Fama first articulated the efficient-market hypothesis in the early 1960s during his time at the University of Chicago Booth School of Business. From an overarching perspective, the efficient market hypothesis theory contends that for investors it is impossible to ‘beat’ the market on a consistent basis. The main reasoning behind this notion is that the market will reflect all available information for the particular investment, such that gaining any sort of edge over other investors is made impossible. This contention does not necessitate that individuals act in rational ways. Indeed, the efficient market hypothesis understands that a number of individuals will both over and under react to available market information. The cumulative impact of these reactions results in market efficiency, as the random reactions will fall proportionally along a normal distribution pattern. In these regards, it’s possible for an individual to be right or wrong about the market, but the market itself is necessarily an accurate reflection of available asset information. Structural Components There are three major versions of the efficient market hypothesis, each of them resting on a different part of a spectrum of efficiency. The first version is the weak-form efficient market theory. Within this perspective all prices on past publically traded assets, including stocks, bonds, and property, already have factored into them all publically available investment information. The semi-strong version of the hypothesis takes this a step further and argues that current asset prices reflect all publically available information and that when new information emerges prices change instantly to reflect this new public information. The third version of the efficient market hypothesis is the strong-form version. The strong-form version of the hypothesis goes even further in that it argues in addition to asset prices immediately reflecting public information, asset prices also instantly reflect insider or otherwise concealed information. Analysis Seminal Literature There are a number of seminal studies that established core elements of the efficient market hypothesis. While Fama first articulated the theory in its modern context, its original formulations were explored as early as the 19th century. Kirman (2009) notes that French mathmetician Louis Bachelier established many of the general tenants of this theory in his ‘Theory of Speculation’ published in 1900. The early years of the 20th century witnessed another prototypical formulation of this perspective in the random walk model. this was a notion that stock prices operated through random steps and as such gaining a long-term predictive edge was