In recent years, with the global economic recession brought about by the COVID-19 pandemic and the turbulence in the international situation, countries have been actively rescuing financial markets. Particularly in China, the national team has invested hundreds of billions of yuan to directly purchase stocks from the stock market to save the market. Research indicates that the direct purchase of stocks indeed leads to an increase in the price of these stocks. Conversely, stocks that are sold within this plan have also clearly experienced a decline. However, it is important to note that this impact is most pronounced in the initial thirty trading days. Over time, the influence gradually diminishes, especially by the fourth thirty-trading-day period, there is a significant drop in stock prices.