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arXiv 0906.5249q-fin.STcond-mat.stat-mechphysics.data-an
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金融协方差矩阵的泛相关性与幂律尾

Universal Correlations and Power-Law Tails in Financial Covariance Matrices

Gernot Akemann, Jonit Fischmann, Pierpaolo Vivo

摘要:

通过比较金融协方差矩阵与随机矩阵预测的个体特征值分布和水平间距来检测普遍性的签名。设计了一个斩波程序,以产生一个统计合奏的资产价格协方差从一个单一的金融数据集的实例。最小特征值和个体间距的局部结果在重新洗牌时间窗口和资产时非常稳定。它们分别与普适Tracy-Widom分布和Wigner surprise符合得很好。这表明了很强的鲁棒性,特别是在光谱的低洼部分,最相关的投资组合选择。相反,单个协方差矩阵的全局谱密度以及所有展开的最近邻间距分布的平均值偏离标准高斯随机矩阵预测。数据是在公平的协议与最近推出的广义随机矩阵模型,相关性显示幂律衰减。

英文摘要:

Signatures of universality are detected by comparing individual eigenvalue distributions and level spacings from financial covariance matrices to random matrix predictions. A chopping procedure is devised in order to produce a statistical ensemble of asset-price covariances from a single instance of financial data sets. Local results for the smallest eigenvalue and individual spacings are very stable upon reshuffling the time windows and assets. They are in good agreement with the universal Tracy-Widom distribution and Wigner surmise, respectively. This suggests a strong degree of robustness especially in the low-lying sector of the spectra, most relevant for portfolio selections. Conversely, the global spectral density of a single covariance matrix as well as the average over all unfolded nearest-neighbour spacing distributions deviate from standard Gaussian random matrix predictions. The data are in fair agreement with a recently introduced generalised random matrix model, with correlations showing a power-law decay.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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