Dynamic topology and allometric scaling behavior on the Vietnamese stock market

The impact of the Vietnamese financial crisis during 2011-2012 into the stock market was revealed by a structural change of the minimum spanning tree (MST) constructed from the daily stock price. We found that the MST has a star-like structure during this period, similar to that of the German market during the worldwide financial crisis of 2007-2008 (M. Wiliski et al., 2013), and a hierarchical scale-free structure for the rest of time. In addition, we investigate the market from a complex network perspective by analyzing the allometric scaling behavior. We found that all networks have the allometric scaling property, with exponent η ranging from 1.213±0.013 during the financial instability period to about 1.357±0.011 in normal time. These values correspond to a complex “dimension” of the financial market of between 3 and 5, which need to be further investigated in the future.