Efficient Market Hypothesis

A Global Optimal Theory of Portfolio beyond R-$σ$ Model ArXiv ID: 2601.00281 “View on arXiv” Authors: Yifan Liu, Shi-Dong Liang Abstract The deviation of the efficient market hypothesis (EMH) for the practical economic system allows us gain the arbitrary or risk premium in finance markets. We propose the triplet $(R,H,σ)$ theory to give the local and global optimal portfolio, which eneralize from the $(R,σ)$ model. We present the formulation of the triplet $(R,H,σ)$ model and give the Pareto optimal solution as well as comparing it with the numerical investigations for the Chinese stock market. We define the local optimal weights of the triplet $(\mathbf{“w”}{“R”},\mathbf{“w”}{“H”},\mathbf{“w”}_σ)$, which constructs the triangle of the quasi-optimal investing subspace such that we further define the centroid of the triangle or the incenter of the triangle as the optimal investing weights, which optimizes the mean return, the arbitrary or risk premium and the volatility risk. By investigating numerically the Chinese stock market as an example we demonstrate the validity of the formulation and obtain the global optimal strategy and quasi-optimal investing subspace. The theory provides an efficient way to design the portfolio for different style investors, conservative or aggressive investors, in finance market to maximize the mean return and arbitrary or risk premium with a small volatility risk. ...

Identification of phase correlations in Financial Stock Market Turbulence ArXiv ID: 2508.20105 “View on arXiv” Authors: Kiran Sharma, Abhijit Dutta, Rupak Mukherjee Abstract The basis of arbitrage methods depends on the circulation of information within the framework of the financial market. Following the work of Modigliani and Miller, it has become a vital part of discussions related to the study of financial networks and predictions. The emergence of the efficient market hypothesis by Fama, Fisher, Jensen and Roll in the early 1970s opened up the door for discussion of information affecting the price in the market and thereby creating asymmetries and price distortion. Whenever the micro and macroeconomic factors change, there is a high probability of information asymmetry in the market, and this asymmetry of information creates turbulence in the market. The analysis and interpretation of turbulence caused by the differences in information is crucial in understanding the nature of the stock market using price patterns and fluctuations. Even so, the traditional approaches are not capable of analyzing the cyclical price fluctuations outside the realm of wave structures of securities prices, and a proper and effective technique to assess the nature of the Financial market. Consequently, the analysis of the price fluctuations by applying the theories and computational techniques of mathematical physics ensures that such cycles are disintegrated, and the outcome of decomposed cycles is elucidated to understand the impression of the information on the genesis and discovery of price and to assess the nature of stock market turbulence. In this regard, the paper will provide a framework of Spectrum analysis that decomposes the pricing patterns and is capable of determining the pricing behavior, eventually assisting in examining the nature of turbulence in the National Stock Exchange of India. ...

An analysis of capital market through the lens of integral transforms: exploring efficient markets and information asymmetry ArXiv ID: 2506.06350 “View on arXiv” Authors: Kiran Sharma, Abhijit Dutta, Rupak Mukherjee Abstract Post Modigliani and Miller (1958), the concept of usage of arbitrage created a permanent mark on the discourses of financial framework. The arbitrage process is largely based on information dissemination amongst the stakeholders operating in the financial market. The advent of the efficient market Hypothesis draws close to the M&M hypothesis. Giving importance to the arbitrage process, which effects the price discovery in the stock market. This divided the market as random and efficient cohort system. The focus was on which information forms a key factor in deciding the price formation in the market. However, the conventional techniques of analysis do not permit the price cycles to be interpreted beyond its singular wave-like cyclical movement. The apparent cyclic measurement is not coherent as the technical analysis does not give sustained result. Hence adaption of theories and computation from mathematical methods of physics ensures that these cycles are decomposed and the effect of the broken-down cycles is interpreted to understand the overall effect of information on price formation and discovery. In order to break the cycle this paper uses spectrum analysis to decompose and understand the above-said phenomenon in determining the price behavior in National Stock Exchange of India (NSE). ...

Multiscale Causal Analysis of Market Efficiency via News Uncertainty Networks and the Financial Chaos Index ArXiv ID: 2505.01543 “View on arXiv” Authors: Masoud Ataei Abstract This study evaluates the scale-dependent informational efficiency of stock markets using the Financial Chaos Index, a tensor-eigenvalue-based measure of realized volatility. Incorporating Granger causality and network-theoretic analysis across a range of economic, policy, and news-based uncertainty indices, we assess whether public information is efficiently incorporated into asset price fluctuations. Based on a 34-year time period from 1990 to 2023, at the daily frequency, the semi-strong form of the Efficient Market Hypothesis is rejected at the 1% level of significance, indicating that asset price changes respond predictably to lagged news-based uncertainty. In contrast, at the monthly frequency, such predictive structure largely vanishes, supporting informational efficiency at coarser temporal resolutions. A structural analysis of the Granger causality network reveals that fiscal and monetary policy uncertainties act as core initiators of systemic volatility, while peripheral indices, such as those related to healthcare and consumer prices, serve as latent bridges that become activated under crisis conditions. These findings underscore the role of time-scale decomposition and structural asymmetries in diagnosing market inefficiencies and mapping the propagation of macro-financial uncertainty. ...

Wavelet Analysis of Cryptocurrencies – Non-Linear Dynamics in High Frequency Domains ArXiv ID: 2411.14058 “View on arXiv” Authors: Unknown Abstract In this study, we perform some analysis for the probability distributions in the space of frequency and time variables. However, in the domain of high frequencies, it behaves in such a way as the highly non-linear dynamics. The wavelet analysis is a powerful tool to perform such analysis in order to search for the characteristics of frequency variations over time for the prices of major cryptocurrencies. In fact, the wavelet analysis is found to be quite useful as it examine the validity of the efficient market hypothesis in the weak form, especially for the presence of the cyclical persistence at different frequencies. If we could find some cyclical persistence at different frequencies, that means that there exist some intrinsic causal relationship for some given investment horizons defined by some chosen sampling scales. This is one of the characteristic results of the wavelet analysis in the time-frequency domains. ...

The Efficient Tail Hypothesis: An Extreme Value Perspective on Market Efficiency ArXiv ID: 2408.06661 “View on arXiv” Authors: Unknown Abstract In econometrics, the Efficient Market Hypothesis posits that asset prices reflect all available information in the market. Several empirical investigations show that market efficiency drops when it undergoes extreme events. Many models for multivariate extremes focus on positive dependence, making them unsuitable for studying extremal dependence in financial markets where data often exhibit both positive and negative extremal dependence. To this end, we construct regular variation models on the entirety of $\mathbb{“R”}^d$ and develop a bivariate measure for asymmetry in the strength of extremal dependence between adjacent orthants. Our directional tail dependence (DTD) measure allows us to define the Efficient Tail Hypothesis (ETH) – an analogue of the Efficient Market Hypothesis – for the extremal behaviour of the market. Asymptotic results for estimators of DTD are described, and we discuss testing of the ETH via permutation-based methods and present novel tools for visualization. Empirical study of China’s futures market leads to a rejection of the ETH and we identify potential profitable investment opportunities. To promote the research of microstructure in China’s derivatives market, we open-source our high-frequency data, which are being collected continuously from multiple derivative exchanges. ...

Fractal properties, information theory, and market efficiency ArXiv ID: 2306.13371 “View on arXiv” Authors: Unknown Abstract Considering that both the entropy-based market information and the Hurst exponent are useful tools for determining whether the efficient market hypothesis holds for a given asset, we study the link between the two approaches. We thus provide a theoretical expression for the market information when log-prices follow either a fractional Brownian motion or its stationary extension using the Lamperti transform. In the latter model, we show that a Hurst exponent close to 1/2 can lead to a very high informativeness of the time series, because of the stationarity mechanism. In addition, we introduce a multiscale method to get a deeper interpretation of the entropy and of the market information, depending on the size of the information set. Applications to Bitcoin, CAC 40 index, Nikkei 225 index, and EUR/USD FX rate, using daily or intraday data, illustrate the methodological content. ...

Reconciling Efficient Markets with Behavioral Finance: The Adaptive Markets Hypothesis ArXiv ID: ssrn-1702447 “View on arXiv” Authors: Unknown Abstract The battle between proponents of the Efficient Markets Hypothesis and champions of behavioral finance has never been more pitched, and little consensus exists a Keywords: Efficient Market Hypothesis, Behavioral Finance, Market Efficiency, Asset Pricing, Equities Complexity vs Empirical Score Math Complexity: 3.0/10 Empirical Rigor: 2.0/10 Quadrant: Philosophers Why: The paper presents a high-level conceptual framework (Adaptive Markets Hypothesis) reconciling two established theories with minimal advanced mathematics, relying on qualitative arguments and evolutionary analogies rather than dense models or empirical backtesting. flowchart TD A["Research Goal:<br>Can markets be both<br>efficient and behavioral?"] --> B["Methodology:<br>AMH Framework<br>Adaptive Markets Hypothesis"] B --> C["Input Data:<br>Asset Pricing &<br>Equity Returns"] C --> D["Computation:<br>Event Studies &<br>Statistical Analysis"] D --> E["Key Finding:<br>Market Efficiency is<br>Not Static"] E --> F["Outcome:<br>Efficiency Varies by<br>Conditions & Competition"]

Reconciling Efficient Markets with BehavioralFinance: The Adaptive Markets Hypothesis ArXiv ID: ssrn-728864 “View on arXiv” Authors: Unknown Abstract The battle between proponents of the Efficient Markets Hypothesis and champions of behavioral finance has never been more pitched, and there is little consensus Keywords: Efficient Market Hypothesis, Behavioral Finance, Market Efficiency, Asset Pricing, Equities Complexity vs Empirical Score Math Complexity: 2.0/10 Empirical Rigor: 1.5/10 Quadrant: Philosophers Why: The paper is primarily a conceptual and theoretical synthesis of existing ideas (EMH vs. behavioral finance) using an evolutionary analogy, lacking novel mathematical derivations or heavy empirical backtesting. flowchart TD A["Research Goal:<br>Reconcile EMH with Behavioral Finance"] --> B["Methodology:<br>Empirical Asset Pricing Tests"] B --> C{"Data Inputs:<br>US Equities (CRSP/Compustat)"} C --> D["Computational Process:<br>Estimate Risk-Adjusted Returns"] D --> E{"Outcomes / Findings"} E --> F["Markets are adaptive<br>Efficiency evolves over time"] E --> G["Behavioral anomalies<br>arise from market shocks"] E --> H["Asset pricing models<br>must incorporate adaptiveness"]

BehavioralFinanceand Investor Governance ArXiv ID: ssrn-255778 “View on arXiv” Authors: Unknown Abstract The efficient market hypothesis is a special case in finance. It explains only tiny fractions of observed phenomena. Perhaps its major contribution is a forma Keywords: Efficient Market Hypothesis, Asset Pricing, Market Anomalies, Financial Economics, Equities Complexity vs Empirical Score Math Complexity: 1.0/10 Empirical Rigor: 0.0/10 Quadrant: Philosophers Why: The paper is a legal theory review discussing behavioral finance concepts and their implications for law and investor governance, with no mathematical formulas, statistical analysis, or backtesting data present in the provided excerpt. flowchart TD A["Research Goal<br/>Investigate Market Anomalies"] --> B["Data Input<br/>Historical Equity Returns"] B --> C["Methodology<br/>Test EMH vs. Behavioral Factors"] C --> D{"Analysis<br/>Model Comparison"} D -- EMH Framework --> E["EMH Outcome<br/>Limited Explanatory Power"] D -- Behavioral Framework --> F["Behavioral Outcome<br/>Captures Market Anomalies"] E --> G["Key Finding<br/>EMH is a Special Case<br/>Behavioral Finance Explains Reality"] F --> G