論對市場詐欺理論於美國法制動態與我國實務運用更迭

The Evolution of Fraud-on-the-Market Theory in the United States and Taiwan

經由美國最高法院判決與學說對「對市場詐欺理論」(“Fraud-on-the-Market” Theory)之重新認定與分析，以及近幾年我國實務對該理論之運作更迭，進而重新檢視我國現行證券交易法之證券詐欺規定，且本文進一步釐清美國法制適用該理論之正確軌跡。例如，是否全部的投資人(All Investors)皆可一律依該理論推定具有「交易因果關係」？抑或，僅具效率市場始能適用該理論？效率市場的判斷是否又僅依據交易量多寡為唯一判斷標準？倘若可不以效率資本市場為唯一前提，如何證明系爭股票價格乃係遭到不實消息所產生扭曲？近期美國判例法將澄清此一疑問，且認為應將關鍵審查要件置於探討「不實資訊是否扭曲個別股票價格」。然而，如何證明個別證券價格與不實消息間之因果關係，價格扭曲之證明標準應採嚴格要件或寬鬆認定？以及，在我國實務上，原告如何證明「損失因果關係」？又被告可否舉反證推翻「損失因果關係」？甚或是「損失因果關係」舉證責任本應由何人負擔？此些問題，本文試圖從比較法研析中尋求答案。蓋因是否構成美國法上證券詐欺，除具備侵權行為要件外，尚須符合「交易因果關係」與「損失因果關係」，而此二因果關係在美國法制上有不同檢視標準與舉證責任分配，且原告在提起證券詐欺團體訴訟前，須於訴訟前置程序中(Pretrial)取得法院認許團體訴訟，始有讓原告適用「對市場詐欺理論」之空間，與我國原告直接向法院提起訴訟，程序進行方式有其根本上的差異性，如無將該理論之適用界定清楚，多一分則恐有助長證券訴訟的濫用，少一分亦可能造成無法嚇阻行為人利用不實消息獲利。是此，本文仍建議證券交易法修法明文化證券詐欺關於舉證責任配置規定，而非依個案視情況是否適用民事訴訟法第277條但書規定，或交由承辦法官心證而將判決結果繫於未決。

This article focus on the relevant issues relating to applications of U.S. law’s fraud-on-the-market theory (the Theory) in Taiwan’s cases involving securities fraud. There are so many unsolved questions about the Theory’s applications, even in the United States. The Theory presumes a transaction causation which can help securities victims get around difficulties to prove their transaction at issue rely on the defendants’ misleading behaviors. One may ask how we can apply the Theory even in a not so efficient market. Recent U.S. cases clarified this question and held we should ask “whether a misstatement distorted the price of the affected security.” However, it remains unclear how to prove the existence of causation between alleged fraud and price of a given stock. Moreover, this article is expected to discuss issues with respect to loss causation because U.S. judicial opinions also diverge. As a civil law jurisdiction, Taiwan’s courts tend to make decisions according to statutes rather than legal theories and principles. Without clear guidance, courts may find difficulties while applying the Theory and it is easy to conclude that judicial opinions would be different form court to court. To sum up, this article will analyze relevant issues about applications of the Theory in Taiwan and U.S. and end up with suggestions for Taiwan’s future legal reform in this regard.