我國上市櫃公司，進行減資時主要採行下列三種方式：（一）彌補虧損減資（二）現金減資（三）買回庫藏股減資。本研究採用訊號發射假說，檢視2001年至2011 年間，上市櫃公司實施現金減資以及庫藏股減資減資後的市場反應，針對上市櫃公司在進行減資宣告後對股價是否具有短期影響，並檢視減資公司長期經營績效是否有顯著改善。實證結果顯示宣告減資公司在短期內股價報酬率確實具有正向顯著的效果。長期而言，辦理減資之公司若於減資當年度經營績效衰退程度越大，後續年度經營績效改善情況越佳，顯示減資行為確實傳遞經營績效能獲得改善的訊號。減資比率與經營績效未存在顯著的關聯性，係與Grullon and Michaely（2004）的結論相同。

The capital decrease objectives can be categorized into three aspects in Taiwan stock market: first, eliminate accumulated losses; second, return cash to the shareholder; third, stock repurchases. This paper adopted signaling hypothesis to test the stock market reaction of capital decrease firms from 2001 to 2011. This study discussed the announcement effect of stocks repurchase and tested whether firms improve long-term performance. The empirical evidence showed positive abnormal return for announcement effect. In the long term, for the capital decrease firms with more decreasing operating performance, the performance improvement is more conspicuous. It indicated that management used open-market share repurchases to signal better prospects.