一般投資人最擔心的，就是遇上無預警爆發的地雷股，造成投資的損失及市場的牽連及震盪。觀察近期幾件重大的地雷公司事件，可以發現其中一項共通點即是『財務主管、查帳會計師連續更換，董事、監察人辭職或解任』。董監事、財務主管與查帳會計師，是相當了解公司運作的內、外部人士，當他們選擇辭職與解除委任關係，釋放出內部公司運作偏離常軌的訊息，便可視為公司一個重要的負面警訊。 本研究以台灣上市公司公告財務主管異動為樣本，將異動原因分類，利用會計績效指標及市場績效指標來衡量公司的經營成果及對股東財富的影響。實證結果最重要的發現是，在不同異動原因下，市場對該消息的反應也會有所不同，最明顯是在非自願異動的樣本中，異動後二天到異動後三十天，累積平均超常報酬率（CAR）顯著為負，表示投資人若認為公司財務主管異動屬於非自願性，於事件發生日前後幾天到市場放空股票，在風險及成本不計下將有獲利，似乎代表著公司公布此類異動的理由及新任主管所帶來的不確定性，嚴重影響到市場對公司的信心。 Investors are generally worried about sudden huge losses as a result of un-warned adverse corporate events. Recent adverse corporate events in Taiwan have one thing in common ---- that is, “the continuous replacement of Financial Officers and Auditors, and the resignation or termination of Directors and Chief of Auditors”. Directors, Chief of Auditors, Financial Officers and Auditors are usually the ones who know the operation better than others. When these people opt to resign or relinquish their responsibilities assigned, their actions signal that a company’s operation may possibly deviate from normal. This scenario could be viewed as an important negative sign of the corporation. We study the official resignation announcements of the CFOs by listed companies in Taiwan. The study attempts test the impact of such events on the stock and operation performances of a firm. We find that different reasons that the CFOs resign will result in different stock prices and operation performances reactions. For involuntary resignations, the cumulative abnormal returns (CARs) are significant negative from 2 to 30 days after the event. This indicates that if the CFO’s resignation is involuntary, investors regard it as time to sell off in the market. This seems to indicate that announcements of the involuntary resignations of CFOs will generate great uncertainly about the company’s future and hence reduce the market’s confidence in the corporation.
