Analyzing data from Chinese online interactive investor platforms, our study reveals that Minority Shareholder Activism (MSA) effectively curtails informed insider trading by voting with their hands or feet, particularly in firms with weaker external monitoring. MSA not only reduces the profitability of insider trading but also encourages firms and regulators to implement stricter ex-post disciplinary measures. Moreover, MSA alleviates the negative impact of insider trading on the stock market by enhancing stock liquidity, increasing stock price informativeness, and reducing crash risk.

This study investigates the impact of investor attention on stock market reactions to ChatGPT using dialogues on the Chinese interactive investor platforms (IIPs). We measure investor attention by the number of investors’ questions toward ChatGPT on the IIPs and categorize the firms’ answers as Investing, Speculative, and Absent. The research reveals positive and statistically significant market reactions surrounding the initial questions that occur before firm responses. Positive abnormal returns are also observed around the initial answer dates, with Investing firms evoking the highest market response, followed by Speculative firms, and Absent firms exhibiting the lowest reactions. Furthermore, positive market reactions persist even as firms modify their ChatGPT involvement statements or face stock exchanges inquiries, suggesting that the stock price upswing may primarily be fueled by ChatGPT-related mania. Our findings imply the potential of ChatGPT fervor: collusion caused by investor attention to ChatGPT and firm’s responses catering to investors.