Talk:Random walk hypothesis

message: The introduction should specify that the so-called "hypothesis" is in fact not really a hypothesis, but a modelling assumption.
Everyone in finance knows that the data does not follow a random walk. Random walk models, however, simplify mathematical analyses, and may furthermore yield useful insights.
Compare with the so-called "Laws" of Thermodynamics (which are actually probabilistic outcomes), or the "Theory" of Relativity, which is well-supported by data, for precedents in which the conventional language misrepresents the role played by the model.  —Preceding unsigned comment added by 211.28.54.169 (talk) 00:43, 20 April 2009 (UTC)
replies: text: I am looking forward to how you want to use data analysis to prove that something is or is not random.  — Preceding unsigned comment added by 119.228.239.82 (talk) 13:36, 10 April 2017 (UTC)
thread_title:  Clarification required in introductory paragraph 

message: Please note that the sections "A non-random walk hypothesis" and "Random walk hypothesis vs. market trends" essentially repeat each other, and should be merged. Askari Mark (Talk) 05:04, 1 February 2007 (UTC)
thread_title:  Repetitive sections 

message: 1. How has it been shown that the financial markets are a random walk? Was there a study done that showed no correlation between past and future price movement?
2. I'd like some clarification of the hypothesis: does it refer only to the unpredictability of a single subsequent price from the immediately preceding one? What about price X time steps into the future?
3. A comment on "Testing the Hypothesis:" The first example (coin toss) is surely not a test of the hypothesis. It is only a test of the "chartist," it says nothing about financial markets.
Mwtzz (talk) 20:49, 8 January 2008 (UTC)
thread_title:  Some comments and questions 

message: The NBA example is truly unneccessary to include. Clearly whether stock markets can be modelled as a random walk has nothing to do with whether basket ball shots can be so modelled, and the example hardly illuminates anything. 
Also it might be interesting to note that volatility tends to cluster. (See eg the ARCH model.) This is not compatible with a random walk but does not mean that prices are predictable.  —Preceding unsigned comment added by 65.95.27.133 (talk) 17:01, 7 November 2008 (UTC)
thread_title:  Some notes 

message: There's another hypothesis with the same name proposed by the Robert Hall. It concerns the consumption function. Should we have a new page for that or just include it here? __earth (Talk) 05:28, 22 February 2009 (UTC)
thread_title:  Robert Hall's random walk hypothesis 

message: "Testing the hypothesis" section has nothing to do with thesting the RWH and is just an anectode. It should rather contain a summarry of test's performed pre-EMH (Cowles; Kendall), a short description of Bachelier-Osborne's and Mandelbrot's  definition of the Random Walk, Fama's findings. Further, we've got a number of studies reporting predictability of stock returns: Rozeff & Kinney; French & Roll and variance ratio test (Lo & McKinley) mentioned in the subsequent section, that should be a part of this one (since the alternative hypothesis to RW is obviously non-random walk). And after Brock et al. () we have a real boom of studies providing evidence that simple chartist rule are working.
Zirr (talk) 21:14, 3 July 2019 (UTC)
thread_title:  Testing the hypothesis