This study investigates the impact of China’s ban on the Korean wave (BKW) on domestic entertainment stock prices. The ban was triggered by the Korean government’s decision to deploy a terminal high-altitude area defence in Korea in 2016. We explore the statistical equilibrium of stock returns using the entropy applied with symbolic time series analysis. Moreover, we confirmed that the BKW harmed the pricing complexity of Korean entertainment stocks. Our finding can be understood as a monotonous stock price pattern because the market information was not reflected efficiently due to the decrease in transactions among investors concerned about the negative impact on the entertainment sector.