承銷商存在新上市公司股票(IPOs)安定操作之誘因,但其為避免操作無效,故並不會向市場揭露該行為的相關資訊。基於此安定操作的隱蔽性特徵,本研究主張偵測IPOs是否受到該行為的干預,應回歸到安定操作之精神,即納入股價波動性變化因素。本研究另一個重要的目的,係為釐清承銷商執行安定操作究竟是為降低IPOs上市初期資訊不對稱程度,或僅為管理初期股價的操弄行為,故擬以長期觀點重新檢視之。實證結果顯示,針對被認定符合安定操作條件的IPOs而言,即使其初期績效較為不佳,但長期績效並未有明顯低落之現象。據此,吾人應能以正面解釋承銷商進行安定操作的動機,此對於穩定初期股價有其實質貢獻。
As previous researches claim, underwriters have incentives to stabilize IPOs' initial performance. To avoid unexpected failure, most underwriters, nevertheless, do not reveal relevant information on stabilizing operations. Grounding on the attribute of opacity, we incorporate price volatility into our model, reverting to the essence of price stabilization, to investigate if such act sways IPOs' performance. The other substantial purpose of this study is to differentiate whether underwriters try to diminish the depth of information asymmetry or simply manipulate initial IPOs' price through the implication of price stabilization. We, thus, re-examine the results from the perspective of long-term performance of IPOs. Our empirical work indicates that IPOs which satisfy the criteria of price stabilization do not suffer significant inferior long-term returns yet with poor initial performance. Our evidence demonstrates that price stabilization has definite dedication to steady security price on the early stage of an IPO.