價格影響乃是Basic案詐欺市場理論的核心，此在Halliburton II案及Goldman Sachs案中都反覆獲得確認。若欲從價格影響的角度切入，對Basic案詐欺市場理論進行解構，則應聚焦於其所結合的「市場模式」與「普通法詐欺」。市場模式為詐欺市場理論最初提出時所標舉之理論願景，旨在建構一套嚴謹、統一、可受實證支持的分析架構；而在美國聯邦最高法院的論述中，詐欺市場理論仍然是跟隨著普通法詐欺的基本架構，並維繫與普通法詐欺間的連續性。故Basic案詐欺市場理論下的「信賴推定」，係基於普通法詐欺的基礎，而在市場模式下，已改變為「價格影響推定」，其證明方法更高度仰賴於價格證據（尤其是事件研究法）。詐欺市場理論已經從本質上改變了請求的性質，轉換成「市場基礎的請求」。於我國法上考慮應否採納詐欺市場理論時，對此應有通盤之瞭解。<br>詐欺市場理論對於證券資訊不實訴訟的影響，更已經超出對於信賴要件的重新表述。在市場模式下，並沒有必要進行關於重大性、信賴、因果關係和損害的獨立調查，調查重點只在於：市場價格是否有因為不實資訊而受到影響，亦即是否有「價格扭曲」之存在，而且原告至多只會受到價格扭曲（或價格影響）程度的損害。對於我國法制而言，若未妥適釐清，即引入美國法的相關討論，勢將對於損失因果關係之認定，與損害賠償計算等，造成概念及運作上混淆，實為吾人應審慎思考的。

Price impact lies at the core of the fraud-on-the-market theory in Basic, a principle repeatedly reaffirmed in Halliburton II and Goldman Sachs. To deconstruct Basic’s fraud-on-the-market theory from the perspective of price impact, one must focus on its dual foundation:“the market model”and“common law fraud.”The market model represents the original theoretical ambition of the fraud-on-the-market theory—to construct a rigorous, unified, and empirically testable analytical framework. At the same time, in the jurisprudence of the U.S. Supreme Court, the fraud-on-the-market theory continues to follow the basic structure of common law fraud and maintains continuity with it.<br>Accordingly, while Basic’s presumption of reliance is rooted in common law fraud, under the market model it has evolved into a presumption of price impact. The evidentiary method under this approach relies heavily on price evidence—especially event studies. The fraud-on-the-market theory has, in essence, altered the nature of the cause of action, transforming it into a“market-based claim.”Thus, when considering whether to adopt the fraud-on-the-market theory under Taiwanese law, a comprehensive understanding of this transformation is essential.<br>The influence of the fraud-on-the-market theory on securities misrepresentation litigation extends far beyond a rearticulation of the reliance requirement. Within the market model, it is deemed unnecessary to independently investigate materiality, reliance, causation, or damages. The focus of inquiry shifts solely to whether the market price was affected by the misrepresentation—that is, whether there was a“price distortion.”At most, the plaintiff suffers damage only to the extent of that distortion (or price impact). If Taiwanese law were to adopt this aspect of U.S. doctrine without rigorous scrutiny, it could result in both conceptual and practical confusion—particularly in the determination of loss causation and the calculation of damages. This is indeed an issue that warrants further thorough and careful consideration.