Macroeconomic Policy-Incorporated Jump Dynamics in High-Frequency Stock Index Markets

The Shanghai Composite Index (SSE), as a representative composite index of listed companies on the Shanghai Stock Exchange, is a core observation indicator of the systematic risk and price discovery mechanism in China's capital market. It includes various industries such as finance, energy, and industry, and can effectively depict the overall dynamic changes of the market This study selected intraday high-frequency data from January 2, 2024 to December 31, 2024. In order to accurately capture tail extreme events (such as liquidity shocks or policy driven jump risks) and overcome the discontinuity problem caused by low-frequency sampling, a balanced data frequency with 5-minute intervals was adopted The final dataset covers 48 observation points for each trading day, obtaining a total of 11656 observations of index returns within effective days Meanwhile, Monetary policy and real estate policy are the core tools of macroeconomic regulation. The former directly affects market liquidity, interest rates, and financing costs, while the latter, as a pillar industry of China's economy, directly affects market stability. Therefore, this article takes the release of information on monetary policy and real estate policy as representative events of macroeconomic policy, and adopts the event study method (Sorescu et al. (2017)) to ultimately determine 25 positive policies and 16 negative policies The price data of the Shanghai Composite Index was purchased from the financial data service of Jinshu Source（ http://www.jinshuyuan.net/pdt/196 ）, the monetary policy announcement was collected from the official website of the People's Bank of China（ http://www.pbc.gov.cn/zhengcehuobisi ）The real estate regulation policy documents are integrated from China Real Estate Network（ http://m.fangchan.com/data ).