本研究探討了內部人設(解)質短期和長期的報酬觀察,在台灣的股票市場對企業廣告費支出的內幕交易事件,有關企業廣告費的支出因為內部人擁有訊息的優勢反應在未來的訊息不對稱。研究依證劵法規定內部人設(解)質後5天內須由主管機關來公告為內部人交易基準日,我們把個股分成兩組分別為有廣告費及沒有廣告費投資的企業,之後並進行報酬差異的比較。 我們研究結果發現,在公告後短期5天有廣告投資報酬是高於沒廣告投資的,證明短期上廣告費訊息不對稱效果影響更強。此外,在長期6個月和12個月來看由於時間週期的拉長廣告訊息效果遞減導致內幕交易的報酬下降,表明企業廣告支出平均在長期時間偏移質押內幕交易獲利混合的副反應。 另一方面,我們也發現有廣告支出的公司短期解質後的報酬是明顯高於設質的報酬,這意味著,企業廣告費支出的負面影響引起解質內幕交易事件。因此,我們的研究結果提供與企業廣告費支出質押內幕交易事件有價值的見解。
This study examine short-and medium-term profits for (un)pledged insider trading events in Taiwan’s stocks markets when corporate spending advertising fees. Because insiders have stronger advantages of information asymmetries about future side effects of corporate spending advertising fees. Additionally, Taiwan regulations make an announcement during five trading dates after (un)pledged insider trading events. We divide stocks into two groups with/without corporate spending advertising fees. Then, we compare trading behaviors for those firms with/without corporate spending advertising fees. We find evidence of higher profits pledged insider trading events with corporate spending advertising fees during five days than those without corporate spending advertising fees. It suggests that pledged insiders have stronger advantages of information asymmetries about positive side effects of corporate spending advertising fees. Additionally, pledged insider trading profits with corporate spending advertising fees decrease with pledged time periods, particular during 6 and 12 months respectively. It implies mixed side effects of corporate spending advertising fees during median-term period offset pledged insider trading profits with corporate spending advertising fees. On the other hand, higher profits for unpledged insider trading events with corporate spending advertising fees during five days than for pledged insider trading events. It implies that negative side effects of corporate spending advertising fees lead to unpledged insider trading events. Therefore, our findings should provide valuable insights on pledged insider trading events with corporate spending advertising fees.