內線交易罪保護法益的探索：以市場效率假設及資本資產定價模型為核心

To explore the protected legal interests by insider trading prohibition: Focus on Efficient Capital Market Hypothesis and Capital Asset Pricing Model

長久以來，市場效率假設的概念經常出現在法律文獻中，但是市場效率假設的具體內容與如何去檢驗市場效率等級 –以及更重要的——市場效率假設與內線交易禁止規定之間的關係，一直是處於一個模糊不清的狀態。 事實上，作為檢測市場效率的重要工具，定價模型一直扮演著不可或缺的角色。而資本市場功能的發揮也是以良好的市場效率為前提。從證券交易法禁止內線交易的立場出發，我們可以得知只有半強勢效率才是立法者心目中的理想效率等級。 如果良好的市場效率是資本市場發揮功能的基礎，我們可以合理地推論出內線交易禁止所保護的第一種法益可能是「資本市場功能」或者「投資人對於資本市場的信賴」。 從定價模型承認風險溢價的特性來看，同時也就暗示了財產法益可能是內線交易禁止所保護的第二種法益。在確定了法益的具體內容之後，起碼在對於內線交易的犯罪結構、不法意圖以及訊息公開等若干問題上，我們可以得到一個相對確定的答案。

For a long time the term of the hypothesis of market efficiency is applied in the legal literature, but to check the specific content of this concept and the level of market efficiency, especially more importantly, the relationship between the hypothesis of market efficiency and the prohibition of insider trading are never clarified. In fact, as one of the essential tools for checking the market efficiency pricing model always plays an indispensable role. The proper functioning of the capital market requires that the market is efficient. From the standpoint of the Securities Exchange Law that insider trading be prohibited, it is concluded that only the semi-strong form is the ideal level of market efficiency for legislator. If the good market efficiency is the basis of the functioning of the capital market, we can conclude that the first legal interest, which is protected by prohibition of insider trading, may be 'the functions of the capital market' or 'investors’ confidence in the functioning of the market'. The fact that the pricing model acknowledges the feature of risk premium indicates that the property may be the second legal interest, which is also protected from insider trading prohibition. After the content of these legal interests has been confined, we can get the relative safe answers to the following questions such as the structure of the offense, the illegal intent, or disclosure of inside information.