研究實證發現，在宣告發行可轉換公司債的事件日前後，股價呈現顯著的正面影響，特別是在宣告日前八天，股價上升趨勢明顯，反映出市場對於網通產業的正面預期。這可能由於消息的提前外洩所致，導致內部人或大股東提前操作，推動股價上升。 在可轉換公司債的實際發行日，儘管初期股價保持正向趨勢，發行後股價卻轉為下跌，顯示出市場對於事件發展後的負面情緒。反映出市場對於股權稀釋的擔憂，或是內部人士透過資產交換交易提前鎖定利益，對股價造成負面影響。 在可轉換公司債的轉換日，股價的變化在事件日前後並不顯著，直至轉換日之後，股價開始顯著下跌，顯示市場對於轉換日後的股權稀釋及股票轉換的賣壓明顯感到擔憂。 ;This study examines whether the issuance of convertible bonds by listed and over-the-counter companies in Taiwan′s network communication industry from 2017 to 2023 resulted in abnormal stock returns. The research focuses not only on the traditional announcement date but also considers the impact of the actual issuance date and conversion date on stock prices, with a total of 17 samples. This study employs the event study methodology, using an analysis window of -20 to +20 days to evaluate the effect of these three event dates on the average abnormal return (AR) and cumulative abnormal return (CAR) of stock prices.
Empirical findings show that the announcement of issuing convertible bonds has a significant positive impact on stock prices before and after the event, particularly eight days before the announcement, where there is a clear upward trend in stock prices. This reflects the market′s positive expectations for the network communication industry, possibly due to early leaks of information, leading insiders or major shareholders to act in advance and push up stock prices. On the actual issuance date of the convertible bonds, although stock prices initially maintained a positive trend, they turned downward after the issuance, indicating the market′s negative sentiment following the event. This reflects concerns about equity dilution or insiders locking in profits through asset swap transactions, which negatively impacted stock prices. On the conversion date of the convertible bonds, changes in stock prices were not significant before and after the event. However, after the conversion date, stock prices began to decline significantly, indicating the market′s evident concern about equity dilution and the selling pressure from the conversion of stocks.
