9 research outputs found
Multifractal Analysis on the Return Series of Stock Markets Using MF-DFA Method
Part 3: Finance and Service ScienceInternational audienceAnalyzing the daily returns of NASDAQ Composite Index by using MF-DFA method has led to findings that the return series does not fit the normal distribution and its leptokurtic indicates that a single-scale index is insufficient to describe the stock price fluctuation. Furthermore, it is found that the long-term memory characteristics are a main source of multifractality in time series. Based on the main reason causing multifractality, a contrast of the original return series and the reordered return series is made to demonstrate the stock price index fluctuation, suggesting that the both return series have multifractality. In addition, the empirical results verify the validity of the measures which illustrates that the stock market fails to reach the weak form efficiency
Controlling self-organized criticality in complex networks
A control scheme to reduce the size of avalanches of the Bak-Tang-Wiesenfeld model on complex networks is proposed. Three network types are considered: those proposed by Erdős-Renyi, Goh-Kahng-Kim, and a real network representing the main connections of the electrical power grid of the western United States. The control scheme is based on the idea of triggering avalanches in the highest degree nodes that are near to become critical. We show that this strategy works in the sense that the dissipation of mass occurs most locally avoiding larger avalanches. We also compare this strategy with a random strategy where the nodes are chosen randomly. Although the random control has some ability to reduce the probability of large avalanches, its performance is much worse than the one based on the choice of the highest degree nodes. Finally, we argue that the ability of the proposed control scheme is related to its ability to reduce the concentration of mass on the network. Copyright EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2010
Network evolution based on minority game with herding behavior
The minority game (MG) is used as a source of information to design complex networks where the nodes represent the playing agents. Differently from classical MG consisting of independent agents, the current model rules that connections between nodes are dynamically inserted or removed from the network according to the most recent game outputs. This way, preferential attachment based on the concept of social distance is controlled by the agents wealth. The time evolution of the network topology, quantitatively measured by usual parameters, is characterized by a transient phase followed by a steady state, where the network properties remain constant. Changes in the local landscapes around individual nodes depend on the parameters used to control network links. If agents are allowed to access the strategies of their network neighbors, a feedback effect on the network structure and game outputs is observed. Such effect, known as herding behavior, considerably changes the dependence of volatility σ on memory size: it is shown that the absolute value of σ as well as the corresponding value of memory size depend both on the network topology and on the way along which the agents make their playing decisions in each game round
Stock index dynamics worldwide: a comparative analysis
05.10.Gg Stochastic analysis methods (Fokker-Planck, Langevin, etc.), 05.40.-a Fluctuation phenomena, random processes, noise, and Brownian motion, 02.50.Ey Stochastic processes, 89.65.Gh Economics; econophysics, financial markets, business and management,
Network and eigenvalue analysis of financial transaction networks
87.23.Ge Dynamics of social systems, 89.75.Fb Structures and organization in complex systems, 05.90.+m Other topics in statistical physics, thermodynamics, and nonlinear dynamical systems,
Herding interactions as an opportunity to prevent extreme events in financial markets
A characteristic feature of complex systems in general is a tight coupling
between their constituent parts. In complex socio-economic systems this kind of
behavior leads to self-organization, which may be both desirable (e.g. social
cooperation) and undesirable (e.g. mass panic, financial "bubbles" or
"crashes"). Abundance of the empirical data as well as general insights into
the trading behavior enables the creation of simple agent-based models
reproducing sophisticated statistical features of the financial markets. In
this contribution we consider a possibility to prevent self-organized extreme
events in artificial financial market setup built upon a simple agent-based
herding model. We show that introduction of agents with predefined
fundamentalist trading behavior helps to significantly reduce the probability
of the extreme price fluctuations events. We also test random trading control
strategy, which was previously found to be promising, and find that its impact
on the market is rather ambiguous. Though some of the results indicate that it
might actually stabilize financial fluctuations.Comment: 11 pages, 5 figure
Scaling analysis of time series of daily prices from stock markets of transitional economies in the Western Balkans
In this paper we have analyzed scaling properties of time series of stock market indices (SMIs) of developing economies of Western Balkans, and have compared the results we have obtained with the results from more developed economies. We have used three different techniques of data analysis to obtain and verify our findings: detrended fluctuation analysis (DFA) method, detrended moving average (DMA) method, and wavelet transformation (WT) analysis. We have found scaling behavior in all SMI data sets that we have analyzed. The scaling of our SMI series changes from long-range correlated to slightly anti-correlated behavior with the change in growth or maturity of the economy the stock market is embedded in. We also report the presence of effects of potential periodic-like influences on the SMI data that we have analyzed. One such influence is visible in all our SMI series, and appears at a period T-p approximate to 90 days. We propose that the existence of various periodic-like influences on SMI data may partially explain the observed difference in types of correlated behavior of corresponding scaling functions