Search results for "Bipartite systems"

showing 2 items of 2 documents

Identification of clusters of investors from their real trading activity in a financial market

2012

We use statistically validated networks, a recently introduced method to validate links in a bipartite system, to identify clusters of investors trading in a financial market. Specifically, we investigate a special database allowing to track the trading activity of individual investors of the stock Nokia. We find that many statistically detected clusters of investors show a very high degree of synchronization in the time when they decide to trade and in the trading action taken. We investigate the composition of these clusters and we find that several of them show an over-expression of specific categories of investors.

Social and Information Networks (cs.SI)FOS: Computer and information sciencesPhysicsPhysics - Physics and SocietyQuantitative Finance - Trading and Market MicrostructureBipartite systemFinancial marketFOS: Physical sciencesGeneral Physics and AstronomyNetworkComputer Science - Social and Information NetworksPhysics and Society (physics.soc-ph)tradingComplex networkBipartite systemTrading and Market Microstructure (q-fin.TR)FOS: Economics and businessIdentification (information)big dataSynchronization (computer science)EconometricsNetworks Bipartite systems Financial MarketsFinancial MarketsStock (geology)clustering
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COVARIANCE AND CORRELATION ESTIMATORS IN BIPARTITE SYSTEMS

2017

We present a weighted estimator of the covariance and correlation in bipartite complex systems with a double layer of heterogeneity. The advantage provided by the weighted estimators lies in the fact that the unweighted sample covariance and correlation can be shown to possess a bias. Indeed, such a bias affects real bipartite systems, and, for example, we report its effects on two empirical systems, one social and the other biological. On the contrary, our newly proposed weighted estimators remove the bias and are better suited to describe such systems.

Bipartite systemsBiological systemsWallenius non-central Hypergeometric DistributionCorrelation AnalysisComplex SystemsSocial systemsSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)
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