本研究採事件研究法，探討2024年8月美超微(Super Micro Computer)因遭指控會計操縱並接受美國司法部調查，對台灣高科技產業、AI概念股及美超微概念股異常報酬率之影響，並分析查核品質在事件中的角色。以113年8月28日為事件日，實證結果顯示，多數樣本於事件窗期內呈現顯著負向異常報酬，反映市場對跨國財務醜聞之敏感反應。在查核品質部分，聘用產業專家會計師者會出現更大負向異常報酬，顯示市場質疑其風險辨識能力；而聘用四大會計師事務所者整體表現較佳，但安永查核之AI與美超微概念股仍遭負面衝擊。本研究揭示查核品質於高風險產業中之信任機制，並提供投資人、監管機關與企業決策者實證參考與政策啟示。

This study employs an event study methodology to examine the impact of the August 2024 Super Micro Computer (Supermicro) scandal—triggered by allegations of accounting manipulation and an ensuing investigation by the U.S. Department of Justice—on the abnormal stock returns of Taiwan’s high-tech industry, AI concept stocks, and Supermicro-related concept stocks. The event date is set as August 28, 2024. Empirical results indicate that a majority of sampled firms exhibited significantly negative abnormal returns during the event window, reflecting the market's heightened sensitivity to cross-border financial scandals. In terms of audit quality, firms audited by industry specialist auditors experienced more pronounced negative abnormal returns, suggesting market skepticism toward the specialists’ ability to effectively assess risk. While firms audited by Big Four accounting firms generally showed better performance, those audited by Ernst & Young—particularly within AI and Supermicro-related segments—still suffered significant negative returns. This study highlights the role of audit quality as a trust mechanism in high-risk industries and provides empirical evidence and policy implications for investors, regulators, and corporate decision-makers.

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