本研究以台灣上市櫃公司在2002至2012年的法人說明會和內部人交易事件為樣本，檢定在法說會召開前是否有內部人交易情形? 若有，則法說會之股價反應是否受到內部人交易的影響? 股價反應大小是否與內部人交易規模有關? 內部人若有過度樂觀或過度悲觀，是否影響內部人交易方向與股價反應方向之關係? 實證發現，法說會舉辦前確有內部人交易情形，比例約有45%；在控制公司財務表現、非系統風險以及公司治理之下，內部人買進與賣出持股對法說會股價反應之影響要看內部人是否心理偏誤而定；無心理偏誤下，內部人買進和賣出股票均使股價有正面反應，而買進時比無內部人交易時的股價表現明顯較佳；賣出時對股價的效果也不比未賣出無內部人交易時差。若內部人心理偏誤，則對股價有不利影響：過度樂觀之內部人增加持股，則股價做負面回應；過度悲觀者減少持股，則股價做正面反應，這顯示內部人心理偏誤對公司價值是有損害的。最後，內部人買進股票之交易量，統計上顯著與股價反應呈現正相關，但經濟上不顯著；賣出之交易量則與股價反應無顯著關係。本研究對內部人心理偏誤效果的了解可以提供投資人參考，並增進了解內部人交易所傳達之價值判斷資訊是否可以信賴。

This study uses both conference calls and insider trading events of stock-listed and OTC firms in Taiwan for the period 2002-2012 as a sample to examines: (1) whether there is an insider trading prior to conference calls of firms? (2) if any, whether stock price reactions to conference calls are affected by insider trading? (3) whether stock price reactions are related to insider trading size? and (4) whether insiders’ overoptimism and overpessimism, if any, affect the relation between insider trading direction and stock price reaction direction? The empirical evidence shows that there are considerable insider tradings before conference calls; the proportion is about 45% of conference calls. After controlling for firm’s financial information, nonsystematic risks and corporate governance, the effects of share buying and selling for insiders on the stock price reactions to conference calls depend on whether insider has a psychological bias. If the insider has not psychological bias, then the share buying and selling lead to positive stock price reactions to conference calls; the reactions for share buying are higher than those for no insider trading; the reactions for share selling are not lower than those for no insider trading. If the insider has psychological bias, then the share prices face adverse impacts. When overoptimistic insiders buy self-firm shares, the stock prices face negative reactions to conference calls that hold following insider trading. When overpessimistic insiders sell their shares, the stock price reactions are positive. This evidence indicates the losses of insiders’ psychological biases on firm values. Finally, the number of shares of insider buying is statistically significantly and positively related to stock price reactions, but insignificant in economical perspective. There is no significant relation between the number of shares of insider selling and stock price reactions. Understanding the insider psychological bias effects provides references to investors and knowledge whether the information concerning firm value judgments is reliable.

中文摘要 Ⅰ
英文摘要 Ⅱ
目錄 Ⅳ
表目錄 Ⅴ
圖目錄 Ⅵ
第一章 緒論 1
第一節 研究動機與目的 1
第二節 研究架構 5
第二章 文獻探討與假說建立 6
第一節 內部人交易與法人說明會 6
第二節 內部人心理偏誤與法人說明會之股價反應 8
第三章 研究設計 10
第一節 樣本說明 10
第二節 假說檢定方法 10
第四章 實證結果 16
第一節 樣本與敘述統計 16
第二節 單變量分析 20
第三節 多變量分析 23
第五章 結論 32
參考文獻 33

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