當被告違反證券交易法第二十條之事實獲得確認，原告之損害爲何？向來困擾我國實務界及學界。若證券詐欺損害計算的方法不一，則證券交易法保障公益的目的即無由實現。蓋損害計算方式的不確定，代表被告損害賠償的金額不確定，從而，原告亦無由得知其可受賠償之範圍，進而影響原告利用法院塡補損害之意圖。即使被告違法事實確定，由於損害計計算形成過程的不確定，亦難保其所負擔之賠償金額即爲社會因其違法所負之成本。如此，則嚴重戕害證券交易法藉由民事責任的明文以阻卻行爲人違法亂紀之法規範目的，不論就私權之保障或公益之維護而言，現行法制似未能提供一個有效率的證券詐欺損害賠償方法。本文之立論目的，在於尋求我國關於證券詐欺最適之損害計算方法，藉由成本利益之比較分析，希冀設定一套具實效性的損害計算模式，讓公開發行股票公司任何人得以事先評估因不實財報所須負擔之成本，將遠高於誠實揭露公司資訊所花費之成本，而理性選擇規避被制裁之風險，進而達成保障公益，減少我國公司不實財報的發生比例。

Except for Article 157-1, it seems that neither the parties nor the judges know how to estimate the actual damages in Article 20 of Securities and Exchange Law. The primary goal of securities regulation is to protect the public interest in the integrity of the securities markets. However, if the methodology of damages in securities litigation brought under Article 20 is uncertain, the goal of securities regulation cannot be achieved. in order to deal with the puzzle, the author proposes the gross income loss method as the optimal measure to calculate damages in Article 20 because it is simple and certain. Part Ⅱ of this article provides a brief overview of U.S. methodology of calculating damages at trial. Part Ⅲ explains and evaluates the measure of recovery after the 1995 legislation. Part Ⅳ argues that the gross income loss would be the optimal measure to calculate the damages in Article 20. Finally, part Ⅴ concludes the proposed solution of measuring damages in Article 20.