本文從產品市場的觀點出發，探討企業於產品市場的競爭與其獲利能力，如何影 響企業上市、上櫃掛牌的決策。在適當的條件之下，我們得知生產成本夠低、競爭能力強的 企業，不會因選擇上櫃後財務資訊必需公開，而成為上市公司刻意防堵的對象，從而能轉上 市；生產成本偏高的企業，即使上市公司不防堵也無法上市，因此選擇先行上櫃降低資金成 本，以求提高獲利能力；至於生產成本不高也不低的企業，若選擇上櫃則必然成為上市公司 防堵的目標，從而選擇不上櫃再伺機上市的策略。另一方面，對上市公司而言，則在權衡防堵 對手上市所付出的代價，是否能為阻撓對手上市所增加的獲利彌補過來，從而決定是否對選 擇上櫃的企業採取防堵策略。除此之外，我們也由模型推得當店頭市場加入新上櫃的企業時 ，將視新上櫃企業生產效率的良窳，而對集中市場同產業的公司股價會有不同的影響。

　　　　　For their stocks to be listed and traded in Taiwan Stock Exchange and the OTC market, corporations are demanded to prove, among other things, a sufficient profitability. By far the exchange has set a higher threshold than the OTC market in this respect, and many firms seek to first have their stocks traded in the OTC market and then listed in the exchange. As a great deal of information must be disclosed to prove its profitability, a firm's attempt to have its stock traded in the OTC market may create incentives for its product market rivals to compete more aggressively than before, if the latter's stocks have already been listed in the exchange. We apply a game-theoretic model to show that in the simultaneous equilibrium of the product market and financial market, only high-quality and low-quality firms have their stocks traded in the OTC market, whereas firms of intermediate quality levels will ignore the OTC market and go directly for the stock listing in the exchange. This happens because predation will occur only if the firm newly entering the OTC market proves to have an intermediate quality. We also show that the price response of the exchange to a newly traded stock in the OTC market can be positive or negative, depending upon the disclosed information.