HUANG Jiageng, ZHANG Nianhua
Journal of Central University of Finance & Economics.
2025, 0(3):
114-129.
For the purpose of building a multi-level capital market,China has successively launched a series of systems such as the Shanghai Hong Kong Stock Connect.On the one hand,it has strengthened the interconnectivity of domestic and foreign stock markets,on the other hand,it has also attracted cross-border capital flows,which may affect the stability of the RMB exchange rate.This paper constructs an expanded portfolio model including Shanghai stock market,Shenzhen stock market,Hong Kong stock market and foreign exchange market,and identifies the risk spillover effect of internal and external stock market fluctuations on RMB exchange rate through time-varying spillover index.We found that the interconnection mechanism enhances risk spillovers in the stock market,and the RMB exchange rate market is the net recipient of risk spillovers.In addition,both the Shanghai-Hong Kong Stock Connect and the Shenzhen-Hong Kong Stock Connect have strengthened the risk spillover of the mainland stock market towards the RMB exchange rate in the short term,while the IPO reform of Hong Kong stocks in 2018 attracted mainland enterprises to list in Hong Kong,which also enhanced the risk spillover impact of Hong Kong stocks to the RMB exchange rate.From the mechanism of action,the scale changes of northbound funds and southbound funds under interconnection will directly enhance the risk spillover of domestic and foreign stock markets to foreign exchange markets,while geopolitical risks and stock market panic will strengthen the risk impact through information channels.In addition,the tight liquidity in the capital market and the rising unemployment rate in the real economy will also exacerbate the risk spillover of the stock market towards the RMB exchange rate.Finally,we propose relevant suggestions to reduce stock market risk spillovers and maintain the stability of the RMB exchange rate.