Over the last 2 decades, financial systems have been studied and analyzed from the perspective of complex networks, where the nodes and edges in the network represent the various financial components and the strengths of correlations between them. Here, we adopt a similar network-based approach to analyze the daily closing prices of 69 global financial market indices across 65 countries over a period of 2000–2014. We study the correlations among the indices by constructing threshold networks superimposed over minimum spanning trees at different time frames. We investigate the effect of critical events in financial markets (crashes and bubbles) on the interactions among the indices by performing both static and dynamic analyses of the correlations. We compare and contrast the structures of these networks during periods of crashes and bubbles, with respect to the normal periods in the market. In addition, we study the temporal evolution of traditional market indicators, various global network measures, and the recently developed edge-based curvature measures. We show that network-centric measures can be extremely useful in monitoring the fragility in the global financial market indices.

在过去的20年中，已经从复杂网络的角度对金融系统进行了研究和分析，其中网络中的节点和边缘代表了各种金融组成部分以及它们之间的关联强度。在这里，我们采用类似的基于网络的方法来分析2000-2014年期间65个国家/地区的69个全球金融市场指数的每日收盘价。通过构建在不同时间范围内最小生成树上叠加的阈值网络，我们研究了索引之间的相关性。通过对相关性进行静态和动态分析，我们研究了金融市场中的关键事件（崩溃和泡沫）对指数之间相互作用的影响。我们比较和对比了崩溃和气泡期间这些网络的结构，相对于市场的正常时期。此外，我们研究了传统市场指标，各种全球网络指标以及最近开发的基于边缘的曲率指标的时间演变。我们表明，以网络为中心的措施在监控全球金融市场指数的脆弱性方面非常有用。