當投資人解公司的購回股票計書為好消息時，其可能在宣告時已決定買進，但是公司方面是否依計書執行購回，投資人卻需等待執行期間結束後方能知暁。假使公司並確實執行，則當初的宣告行為形同遞傳錯誤訊號，誤導投資人交易方向。本研究假設公司執行股票購回的結果，會形成市場經驗，進而影響其後股票購回計書的宣告效果。為驗上述關係，本研究特別考量各公司執行條件差異性現實際購回結果，發展出可評估股票購回執行程度的方法，之「確實執行指數」。實結果顯示，公司首次確實執行股票購回計書的程度，可以正向解釋其後續進行股票購回宣告續效。再者，由於確實執行觀點立論於市場經驗法則，故此效果的動亦會在第二次股票購回宣告初期即快速産生。此外，本研究也發現股票購回目的與産業別，皆會影響公司確實執行的程度。

It is interesting that when investors consider share repurchase program as good news, they might have already decided to buy in at the announcement, however, whether company did actually execute the plan will only be revealed until the scheduled execution period ends. If managers do not actually execute the plan after the announcement to the market, the announcement will be seen as a falsehood or will transmit false signal that could possibly mislead the investors. This study assumes that the act of not actually executing the repurchase program will result in a market experience that suggests an impression of poor integrity for the company. In order to verify the above mentioned relationship, we especially taken into account the differences of execution condition and exact outcome of repurchase program. We developed a method to measure the execution degree of share repurchase program, namely the "actually executing index" (AEI). The empirical results show that the first actually executed repurchase program can positively explain the following announcement performance of share repurchase programs. In addition, the idea of actual execution is based on the fundamentals of market experience principles. Thus, the effect of the result will soon appear and take place at the initial stage of the second share repurchase announcement. Furthermore, this study also discovered that the degree of actually execution is influenced by the purpose of share repurchase and the industry characteristics.