有別於過去文獻大多側重探討企業本身特性對於資本支出宣告效果之影響,本文則研究資本支出宣告時,市場投資人對於公司所握有之資訊流量大小的差異,是否影響公司股票報酬之異常程度。本文引用非平衡買賣單(order imbalance)作為衡量資訊流量之變數,其優點是能兼顧買賣方向性與資訊流量大小。實證結果顯示公司宣告資本支出時,存在正向之異常報酬,且此正向之異常報酬率與資訊不對稱的程度呈現顯著正向的關係。此外,買方驅動之成交單愈多,則愈能“ 修正”正值之異常報酬;相對地,若賣方驅動之成交單愈多,則愈能“修正”負值之異常報酬。此可能因市場對訊息之看法愈一致時,所表現的價格衝擊愈小。
Differing from the previous literatures which focus on the relationship between capital expenditures and firm attributes, this study explores the relationships between the asymmetric information held by investors and the stock abnormal returns when firm announces its capital expenditures. To improve the defaults of volume not reflecting the whole trades, we employ order imbalance to observe the effect of announcement. The findings indicate that the announcement effect is positive, and there exists a significant positive relationship between asymmetric information and positive abnormal return. In addition, we observe the stronger the buying pressure is, the bigger the adjustment level of positive abnormal return is, and vice versa. That is, the more converging are the investors' viewpoints, the smaller price fluctuation of the stock is.