競價拍賣制度下的案件擁擠現象對上市後證券價格表現之影響

競價拍賣為我國發行新股、現金增資及發行轉（交）換公司債之重要方式。自從2016 年競價拍賣新制實行至今，我國競價拍賣案件數有大幅增加的趨勢，並且隨著可轉換公司債的流行，也逐漸成為公司籌措資金偏好的方式。但與現股市場相比，競價拍賣市場還是具備一定的參與門檻。在此前提之下，進入門檻高的市場與逐年增加的市場案件出現案件擁擠現象，並影響上市後的證券價格表現。本研究採用開標日在2016 年1 月1 日至2023 年10 月30 日之間，臺灣所有以競價拍賣新制成功公開承銷之上市櫃及可轉債發行之案件。建立案件擁擠變數，以研究競價拍賣中案件擁擠程度與期初報酬是否有所關聯。研究發現當案件擁擠程度越高，會使投資人在競價拍賣中的出價偏高，進而導致期初報酬偏低。此一結果對於未來的公開承銷過程中，都是可以去留意的地方。對於公司來說，若要進行公開發行就要針對此因素去進行考量，例如可轉換公司債的轉換價訂定等。對於投資人而言，這項擁擠變數不論是在決定投標價格，或是在證券上市後考慮是否追價購買，都不失為一項有價值的參考指標。

關鍵字

競價拍賣

並列摘要

Competitive bidding auctions are a significant method for issuing new shares, raising capital, and issuing convertible bonds in Taiwan. Since the implementation of the new auction system in 2016, the number of competitive bidding auction cases in Taiwan has shown a significant increasing trend. Along with the growing popularity of convertible bonds, it has gradually become a preferred method for companies to raise funds. However, compared to the stock market, the auction market still has certain participation thresholds. Under this premise, the high entry barriers and the increasing number of market cases have led to crowding out, affecting the post-listing performance of securities prices. This study examines all successful public offerings of listed companies and convertible bonds in Taiwan, under the new auction system, from January 1, 2016, to October 30, 2023. It establishes a crowding out variable to investigate whether there is a relationship between the degree of crowding out in auction cases and initial returns. The study finds that higher degrees of crowding out lead to higher bids from investors, resulting in lower initial returns. These findings have implications for future public offerings. For companies, it is important to consider this factor when planning public issues, such as setting the conversion price of convertible bonds. For investors, this crowding out variable serves as a valuable reference point, whether in determining bid prices during auctions or considering whether to chase prices after securities are listed.