<p>This study focuses on the nuances of stock-level sentiment contagion in the Chinese stock market and its influence on the formation of stock price bubbles. Firstly, sentiment contagion significantly and positively affects stock price bubbles. Secondly, the influence of sentiment contagion on stock price bubbles varies significantly across different industry portfolios, with a more pronounced effect observed within the utility sector. Thirdly, notable disparities in the impact of sentiment contagion on stock price bubbles are also evident across various portfolios of firm characteristics, with the youngest and highest volatility stock portfolios experiencing a more significant impact. Fourthly, the “bubble riding” effect is not uniform across all stock portfolios, with only the highest liquidity portfolio demonstrating this phenomenon. Additionally, sentiment contagion significantly and positively contributes to stock price bubble contagion. Finally, there is a notable distinction in the impact of sentiment contagion within and outside of industries on stock price bubble contagion. In particular, industrial sentiment contagion exerts a more profound influence on contagion of stock prices bubbles. These findings can provide important insights for investors and regulators in dealing with stock-level sentiment contagion.</p>