本篇論文研究1996至2005年期間，共3010樣本數，在美國股票市場宣告增資發行新股事件時，發行者的宣告效果對其競爭者、上下游廠商的市場反應。總體樣本檢定下，競爭者的累積異常報酬在(-1,1)期間顯著為負，期間拉長至(-5,5)時競爭者的累積異常報酬便不顯著。本篇推測效果抵消來自資訊不對稱假說以及成長投資機會假說。在資訊不對稱假說下競爭者有正的異常報酬，成長投資機會假說下競爭者的異常報酬強烈為負，本篇以競爭效果來解釋宣告增資發行新股下競爭者接收發行者的訊號效果的反應。下游廠商的子樣本檢定中，本篇發現下游廠商對公司規模越小的發行者有異常報酬顯著為負的反應，主要原因為規模較小的發行者資訊不對稱程度較大；本篇也發現發行者所屬產業集中度與下游廠商累積異常報酬為正向關係。上游廠商對規模小的發行者其異常報酬也是顯著為負，本篇與以往研究結果一致，發行者宣告增資發行新股後所發射的成長投資機會訊息及降低違約風險的資本結構改善使上游廠商有正的報酬，另一方面，發行者在資本結構改善後對其的議價能力提升也使上游廠商的累積異常報酬減少，整體而言，上游廠商對於發行者宣告增資發行新股的效果為不確定。 This paper uses a sample of 3010 seasoned equity offering (SEO) events from 1996 to 2005 to examine the signal effect of SEO announcement on rivals of the issuer, and on price reaction in customer and supplier industries. The cumulative abnormal return (CAR) to the overall sample of rival is negative on window (-1, 1) while it is offset on window (-5, 5). The sub-sample of rivals provides an evidence to support information asymmetry, growth investment opportunity, and capital structure hypotheses that competitive effect is strong under these theories and negative CAR comes from unfavorable signal and the lower financial leverage of issuer. The negative CAR to the customers mainly derives from small firm size of the issuer and the low-concentrated industry. The abnormal return to the suppliers is unrestricted because the benefits on increase on material demand and decrease on issuer’s default rate are offset by bargaining power of issuer.
