Artificial intelligence (AI) has become a critical driver of China's digital economy, with its integration into industries such as finance, healthcare, manufacturing, and retail accelerating under national policy support. The 13th and 14th Five-Year Plans emphasize the strategic importance of AI, encouraging deep integration with the real economy and promoting high-quality development. However, despite the potential benefits, the high costs and uncertainties associated with AI-driven transformation led some companies to adopt opportunistic behaviors. Rather than committing to substantial investment, these firms may engage in concept speculation—manipulating textual disclosures to exaggerate their involvement in AI without genuine implementation. Such hype exacerbates information asymmetry, fosters speculative market sentiment, and may be ex‐ploited by insiders, especially majority shareholders with privileged access to information.Uncovering the mechanism through which AI-related concept speculation influences majority shareholders' share reductions is of great significance for regulating corporate information disclosure, curbing opportunistic reductions by major shareholders, and preventing systemic risks in capital markets. This paper constructs an AI concept speculation index using text analysis methods and, from the perspectives of information asymmetry and investor bounded rationality, examines the impact of AI concept speculation on major shareholders' share reductions. Empirical tests are conducted using data from Ashare listed companies on the Shanghai and Shenzhen stock exchanges between 2012 and 2020. The results show that majority shareholders are more likely to sell their shares in response to corporate hyping behavior. This tendency is particularly evident in firms with a higher proportion of individual investors, greater stock price volatility, and higher levels of earnings management. Moreover, majority shareholders are more inclined to reduce their holdings when stock prices are relatively elevated.Share reductions by majority shareholders in firms engaged in AI hype increase the risk of stock price crashes, ultimately harming the interests of small and medium-sized investors. The media can play a critical role in identifying such hyping behaviors and providing early warnings to protect retail investors.This study expands the literature on insider trading by introducing AI concept speculation as a novel and underregulated channel through which majority shareholders execute opportunistic reductions. Based on the findings, it offers concrete policy recommendations to strengthen the regulation of AI-related hype and the stock-selling activities of majority shareholders. Ultimately, it provides insights for promoting enterprises to achieve genuine AI transformation and upgrading,thereby ensuring that technological development is rooted in substance rather than speculation.