Table 1. Definition of variables in the propensity score matching method.

Variable type	Variable name	Definition
Dependent variables	The closing price of the target stock.	The closing price of the top five ranked stocks by market capitalization in each sub-industry serves as the dependent variable.
Core explanatory variables	Whether it pertains to the target stock.	Once the target stock is selected, it is assigned a value of 0, while other stocks in the same sub-industry are assigned a value of 1, studying the impact of 1 on 0.
Controlled variables	The opening price.	To control for the opening price variable, the opening prices of all non-target stock companies within the same sub-industry are matched one-to-one with the opening price of the target stock company over time.
	The highest price.	To control for the highest price variable, the highest prices of all non-target stock companies within the same sub-industry are matched one-to-one with the highest price of the target stock company over time.
	The lowest price.	To control for the lowest price variable, the lowest prices of all non-target stock companies within the same sub-industry are matched one-to-one with the lowest price of the target stock company over time.