依證交法規定，「基於職業關係獲悉消息之人」，為內部人，應受內線交易相關法制的規範（第157條之1）。公務員因業務關係獲悉內線消息者，是否包括在內？ 從比較法觀察，依美國聯邦最高法院1997年O'Hagan案(521 U.S. 642)所採用的私取理論，公務員如利用職務上獲取機密消息買賣股票，係違背對其僱主（即政府）的信賴義務(fiduciary duty)，構成內線交易。 歐盟2003年1月發布的指令規定，內部人的範圍，除公司相關人員及股東外，尚包括因僱傭或職業關係，執行其法定（或約定）職責而接觸機密消息之人。指令雖未將公務員明文列舉，惟依學者見解，公務員如因業務關係獲悉消息者，亦為受規範的內部人。 我證交法亦未明定公務員為內部人；實務上，地方法院在禿鷹案的判決，引用美國法的「私取理論」，認涉案公務員「為依職業關係知悉未公開影響股票價格重大消息之人」。 就結論而言，公務員係證交法所定「基於職業關係獲悉消息」的內部人，雖與私取理論相同，但其理由應係以健全市場發展之考量，而非植基於信賴義務的違反，亦不必以O'Hagan案的私取理論做為立論基礎。為期適用明確，證交法「基於職業關係獲悉消息之人」的規定，應修法將其內容做更為明確的規範。

If a government official, knowing information that will substantially affect the price of an issuer's listed stocks, trades in those stocks, is he liable for insider trading? This article discusses the definition of "insider" in the United States, European Union, and Taiwan. Having reviewed relevant cases and regulations, this article finds the following: a、Under the laws of the United States, insider trading liability is premised on the trader's breach of fiduciary duty, either to purchaser or seller of the issuer's stocks, or to the source of the information. While a government official owes no fiduciary duty to the issuer's shareholders, he is in breach of fiduciary duty to the source of the information, and is liable under the misappropriation theory as stated by the U.S. Supreme Court in a 1997 case. (United States V. O'Hagan, 521 U.S. 642). According to the O'Hagan Court, "[a] misappropriator who trades on the basis of material, nonpublic information, in short, gains his advantageous market position through deception; he deceives the source of the information and simultaneously harms members of the investing public" (521 U.S. 656). b、the EU directive on Insider Dealing and Market Manipulation of 2003 provides that any person "by virtue of his having access to the information through the exercise of his employment, profession or duties" is an insider. Although government officials are not enumerated in the directive, scholars widely believe that government officials are subject to insider trading regulation. Unlike the U.S. law, no breach of fiduciary duty is required to make the official liable for insider trading. EU directive makes it clear that the regulation is "to ensure the integrity of Community financial markets and to enhance investor confidence in those markets". c、The ROC Securities and Exchange Act (SEA) stipulates that "a person who has access to the information by virtue of his professional relationship" is an insider. The SEA, however, is silent on whether a government official is included. A recent court decision, citing misappropriation theory, held that a government official who has learned the information by reason of his professional relationship is an insider. d、The term "professional relationship" as used in the SEA is not defined. For the sake of clarity, this article suggests that the SEA be amended to redefine the scope of "insider" in a more specific term.