The Analysis Of Character Of The Complex Network Of The Medium-and-Short-Term Risk Of Stocks With The Nose-Diving Of Shanghai Stock Market

Stock market is a very complex system. Its risk is very immense and hard to estimate and forecast. The subprime crisis aroused the global finance crisis and the nose-diving of A-stock market. This dissertation utilizes the VaR theory to simulate the medium-and-short-term risk of a stock with the persistent falling of the A-stock market, and utilizes the complex network theory to educe the network simulation of the medium-and-short-term risk of a stock. And then this dissertation analysis the medium-and-short-term risk complex network, and educes the results of the statistic characteristic, such as the small-world effect and the scale-free property, and then compares and analysis the results with the existing results of the complex network. Finally, it educes the results by comparing and anglicizing and the analysis and explanation of factual problems.The innovation of this thesis includes that first, it utilizes the VaR theory to simulate the medium-and-short-term risk of a stock, and utilizes the coefficient of correlation of the VaR arrays as the power to create the complex network of the medium-and-short-term risk of stocks for the first time, and simulates the medium-and-short-term risk of a stock well, and provides a new sight for analyzing the relation problems; second, this thesis writes correlated code to analysis the statistic characteristic of the complex network of the medium-and-short-term risk of stocks, and then educes some new conclusions, and explains the factual correlated problems with the conclusions.These conclusions and explanations are following:First, the complex network of the medium-and-short-term risk of stocks has the small-world effect, and the risk of a single stock can spread to other stocks through the network, and the risk of stocks spread abroad easier in a certain group.Second, with the nose-diving of A-stock market, the prices of the stocks affect each other stronger, but the risk of the stocks affects each other weaker.Third, in a shorter term, the probability that the lose of a certain stock is far away to the lose of other stocks is bigger, but in a longer term, the probability is smaller.Forth, the complex network of the medium-and-short-term risk of stocks has not the scale-free property, but at special time, it has the scale-free property.