效率市場概念於美國公司法上之應用

The Application of Efficient Market Under the U.S. Corporate Law

公司作為一種經濟組織態樣，不難想見其理論發展深受經濟學相關理論影響，其中又以效率市場為當中核心。為觀察效率市場於公司法上之應用，本文以效率資本市場假說為中心，探索其在金融經濟學文獻上的發展，以描繪效率市場概念之內涵及其侷限，而在此一基礎上，觀察此一概念在美國法上詐欺市場理論、經營者監督以及內線交易基礎理論等脈絡中之應用，提出「效率」與「市場」在概念上具有歧義性，且有其極限，再進一步將該等觀察應用於股份收買請求權之公平收買價格的討論以為驗證。儘管效率市場在美國公司法理論上的地位有所消長，我國相關論述並不多見，此固然可避免陷入美國法過度盲從效率市場之弊，但亦錯失就此概念進行思辯檢討的機會，則有所不足。

As corporate is deemed an economic organization, the theory of corporate law is deeply affected by economics — especially the concept of efficient market. In order to observe the application of efficient market in the corporate law, this article explores the development of efficient capital market hypothesis (the “ECMH”) to depict the ideal of efficient market, its implications, and limitations. Using fraud on the market theory, scrutiny of management, and insider trading theory as examples, this article observes the application of efficient market in the U.S. corporate law, concluding that the concept of efficient market should be cautiously applied. Based on the above observations, this article further extends its exploration to the determination of fair price. As of now, few discussions about the application of efficient market exist in Taiwan. While such insufficiency allows the corporate law theory in Taiwan to avoid the overextension of efficient market, the opportunity for examination and the insights from such examination is lost as a result.