內線交易的灰色外延 ── 財務經濟觀點下的知情交易

Abstract

內線交易規範存廢的問題從1960年代開始爭辯至今，其間經歷了早期法律上信賴論與市場論的攻防，中期經濟學、資訊財產理論思想的加入。觀諸世界各國，目前為止禁止內線交易的立法與執法已成潮流，但有關為什麼要禁止內線交易、禁止內線交易對市場帶來了什麼好處、保護的對象是誰等等問題，仍然沒有一方能夠完全消除另外一方的疑慮。近期以來科技與研究技術的進步，使得財務研究方法開始興起，並從實證、微觀結構市場的財務經濟觀點，為內線交易議題開啟了新的研究方向。

本文的研究主題 ──「知情交易」，係財務經濟領域在觀察資訊不對稱時，用以描述「一筆交易中之一造挾資訊優勢，與對方為交易而獲得利益」此一現象所使用的概念。傳統法律所禁止的內線交易，在財務經濟理論的脈絡下，也是知情交易的一種，但知情交易卻又比內線交易更為廣泛、模糊，也因此更難以定義。

最常被探討的知情交易就是金融業從業者為確保其穩定的獲利，用盡各種方式來發掘私人資訊、利用資訊優勢在市場上與一般投資人交易因而獲利的行為。由於這類知情交易行為所涉及的資訊開發行為（是否有受託人違反對公司的信賴義務？）、其所獲取的資訊本身的性質（是否構成重大性？機密資訊的公開時點為何？），以及獲取資訊的來源（係其交易股票標的公司的內部人或外部人？）等等，皆跨在傳統內線交易規範射程範圍的邊緣地帶，也因此成為內線交易管制所關注、探討的新重點。

由於金融從業者本身除了參與市場交易以外，亦身負資訊傳遞的任務或其他功能，而具有特殊的地位，故本文將把知情交易的問題獨立於內線交易之外觀察。在探討法律規範或理論如何看待知情交易的同時，除了對照傳統內線交易的相關規範理論外，本文更進一步將財務經濟領域的觀點放入思考框架。在證券交易法規係以「發展經濟、保障投資」（證券交易法第1條）為政策目的之前提下，本文認為最適宜的規範制度，是一套能夠均衡維持各不同市場參與者（而非僅單一投資人，如一般所謂散戶投資人）能夠進入市場的誘因，或滿足他們進入市場的不同目的或效用，並且達到維持、強化資本市場目的的規範框架。

The debate about insider trading started in the 1960s and has continued ever since. In the early days, the debate centered on the legal aspects of the theory of Equal Access and Fiduciary Duty. Later new perspectives from economics and the theory of Property Right in Information joined into the conversation. Although, as a global trend, most countries forbid insider trading behaviors, it still remain in question as to the reason for such policies ── What kind of legal benefits are conferred and who specifically in the market is protected? Recently, with the progress of technology and research techniques, financial methodology has arisen, adding some new ingredients such as empirical studies and market microstructure into the base of the insider trading war.

The topic of this thesis, “informed trading”, is used by the financial economics field in their research to describe the phenomenon where ‘one party uses advantageous information against the other in their transaction and gains abnormal profits’. Under the context of financial economics, the concept of insider trading also falls into the scope of informed trading, though informed trading itself is still a broader and ambiguous notion which therefore is harder to define.

The most commonly discussed kind of informed trading regards those trades engaged in by market professionals and financial institutions. In order to maintain high levels of returns, it is usually essential for them to discover private advantageous information and use it on transactions. Because the related information-digging behaviors (whether there is any trustee in breach of the fiduciary duty owed to the company?), the nature of the information acquired (is it material? the time of disclosure?), and the source of the information (was it inside or outside the company?) … etc. are all standing on the blurred edges of where traditional insider trading regulations can reach, financial type of informed trading turns out to be the new focus of insider trading supervision.

Since market professionals and financial institutions not only participate in ordinary market transactions, but are also responsible for the distribution of information and other alike functions, their special status requires this thesis to stand on an independent and separate view from traditional insider trading theories when analyzing the issue, especially on the view of the financial and economics field. It is the main goal of our Securities and Exchange Act to ‘promote national economic development and to protect investors’, hence this thesis provides that the most pertinent system of regulations is one that can evenly maintain the motives for different kinds of market participants (not solely for less-skilled traders) to enter into the market, satisfy their purposes and utility of trading, and strengthen market efficiency and liquidity.