本論文使用台灣證券交易所的融券、借券放空資料，以探究在盈餘宣告前後的放空交易動態。本文研究發現，無論該次盈餘宣告之結果是負面盈餘驚喜或是正面盈餘驚喜，在盈餘宣告之前、後，皆有異常的放空交易量發生。此外，本論文也研究樣本公司之整體放空交易者所執行的累積異常放空交易量與樣本公司之累積異常報酬間的關係，並發現之間存在一種負向關係。而為了研究不同類別之放空交易者所造成的累積異常放空交易量與累積異常報酬間是否有不同的關係，本論文也將異常放空交易量分為三種類別來檢驗之。研究結果顯示，不同類別放空交易者在盈餘宣告前、後有不同的放空交易行為，而在不同方向之盈餘驚喜時，也有不同的交易行為。

Using short-sale transaction data from Taiwan Stock Exchange, this thesis studies short-selling activities around earnings announcements. There are abnormal short-selling activities both before and after the announcement dates, regardless of whether there is a negative surprise or a positive surprise. In addition, this thesis investigates the relationship between the cumulative abnormal return of the sample stocks and the cumulative abnormal short-selling conducted by short-sellers as a whole, and find a negative relation. To investigate if there are any differences between different types of short-sellers around earnings announcements, this thesis goes further to examine the relation between the cumulative abnormal returns and the cumulative abnormal short-selling conducted by different types of short-sellers. The result shows that short-sellers conduct different strategies before and after earnings announcement and act as different roles with positive and negative surprises, and different types of short-sellers act differently

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