台灣上櫃公司轉上市前後股價行為之研究

本研究以1997年至2019年台灣上櫃轉上市公司為樣本，利用事件研究法探討轉上市掛牌交易前後10個交易日，其股價是否存在顯著異常之反應；並進一步探討不同申請方式、研究期間、產業別、公司規模大小和獲利高低等對其前後股價行為之影響。研究結果顯示無論是全體樣本或是各分類子樣本，其股價在上市掛牌交易日前是呈顯著正向反應，但掛牌後股價則出現不一致顯著波動，顯示台灣上櫃公司轉上市前後股價存在顯著的異常報酬反應，投資人似乎普遍預期會有所謂的「蜜月行情」，促使著投資人於上櫃轉上市掛牌交易前進場購買股票，提升股價，導致投資人對上櫃轉上市訊息過度反應，隨後上市出現價格修正反轉，特別是個別申請轉上市股票存在一致顯著價格反轉，而此結論並不受到研究期間、電子業或非電子業，公司規模大小、公司獲利高低之影響。

關鍵字

上櫃轉上市；股票價格；事件研究

並列摘要

This study uses exchange listed companies from 1997 to 2019 as a sample, and uses the event study method to explore whether there is a significant abnormal effect to their stock prices in the 10 trading days around Exchange listing. Furthermore, this study explores the effects of the application method, study period, industry, firm size and profitability on the stock price behavior around exchange listing. The results show that regardless of whether it is the entire sample or the sub-samples, their stock prices showed a significant positive reaction before exchange listing, but the stock prices after exchange listing showed inconsistent and significant fluctuations. Those results show that there is a significant abnormal reaction around exchange listing. Investors seem to generally expect the so-called "honeymoon market", which push investors to purchase stocks before exchange listing, which increases the stock price, causing investors to overreact to message of exchange listing, and then there is a price reversal after exchange listing. This conclusion is not affected by the study period, industry, firm size, and profitability.