證券詐欺損失因果關係之再思考──從美國最高法院Dura案後之發展觀察

Rethinking Loss Causation in Securities Fraud Claims: From the Observation of Case Developments after Dura

美國聯邦最高法院在2005年的Dura案件，對於損失因果關係採取嚴格的「不實消息更正後股價下跌」證明標準，或許受到Dura案的影響，觀察我國法院對於損失因果關係的證明，若個案中股票之價格於不實消息被更正揭露後，有明顯下跌或悖離大盤及同類股走勢之典型案件，則法院多肯認原告得以此證明投資人損失與公司不實財報間有損失因果關係。然而，損失因果關係的證明在實務上遭遇若干挑戰，包括：如何構成損失因果關係中的「更正揭露」？消息更正揭露後股價沒有明顯下跌時，如何證明損失因果關係？消息更正揭露後股價雖然下跌，但被告抗辯股價下跌乃係因市場其他非詐欺行為因素所導致，是否即足以否定損失因果關係？又消息更正揭露後股價下跌後又回升，如何證明損失因果關係？最後，如果市場上根本沒有「更正揭露」之行為，如何證明損失因果關係？是否有其他替代證明的方法？就此等非典型案件之損失因果關係證明的爭議與挑戰，本文以Dura案後美國巡迴法院就損失因果關係見解的發展，為主要研究與分析的對象，借以反思我國法院在非典型案件中損失因果關係證明的可能途徑與方向，並提出相關建議。

In 2005, the U.S. Supreme Court decision in Dura adopted a strict standard of proof of loss causation, i.e. the truth-then-drop standard. Regarding the issue of how to prove loss causation, the court opinions in Taiwan basically followed the Dura decision. Namely, in a typical case, a plaintiff must allege that he or she purchased a security at an artificially inflated price as a result of fraud, and that upon revelation of the fraud, the stock price declined, causing a loss. However, practically there are some challenges in proving loss causation, for examples, what constitutes a ＂corrective disclosure＂ for purposes of proving loss causation? How to prove loss causation if there is no stock price decline after a corrective disclosure of the fraud? How about if the defendant argues that such stock price decline after a corrective disclosure is due to other factors that are not associated with the fraud? Whether the fact that the stock price recovered soon after the corrective disclosure defeats an interference of economic loss in a securities fraud suit? Or how to prove loss causation if there is no corrective disclosure at all in the market? Are there any other alternatives to prove loss causation? The challenges and difficulties to prove loss causation in the above non-typical cases are the focus of this paper. This paper will study and analyze the opinions of the circuit courts regarding proving loss causation in securities fraud litigations after Dura, as well as provide with the feasible suggestions for the problem of proving loss causation in such non-typical cases in Taiwan.